GDQ33S12B/P

DC-DC Converter Technical Manual V1.7

Quarter-Brick 36 - 72 V Negative
12 V Output 33 A Current
DC-DC Converter Input Logic

Description
The GDQ33S12B/P is an isolated DC-DC
converter that uses an industry nonstandard
quarter-brick structure and features high
efficiency and power density. It provides 12 V
outputs and supports the maximum output
current of 33 A. Two GDQ33S12B/Ps can be
connected in parallel to provide the maximum
output current of 54 A. The GDQ33S12B/P
communicates over PMBus 1.1 to support
monitoring and alarm reporting functions, such as
monitoring the output voltage and current, input
voltage, digitally adjusting the voltage, and
activating software.

Operational Features
 Input voltage: 36 - 72 V
 Output current: 0 - 33 A
 Rated output voltage: 12 V
 Efficiency: 96.0% (12 V, 16.5 A) GDQ33S12B/P

Mechanical Features Key Features

 Industry nonstandard quarter-brick (D x W x H,  PMBus Revision 1.1 compliant
with a baseplate): 57.9 mm x 36.8 mm x 12.7
mm (2.28 in. x 1.45 in. x 0.50 in.) Monitoring Features
 Weight: about 66 g
 Activates hardware and software
 Digitally adjusts the voltage
Protection Features  Monitors the input and output voltages
 Input undervoltage protection  Monitors the output current
 Output overcurrent protection (hiccup mode)
 Output short circuit protection (hiccup mode) Safety Features
 Output overvoltage protection (hiccup mode)  UL60950-1 and CSA C22.2 No. 60950-1-07
 Overtemperature protection (self-recovery)  Meet UL94V-0 flammability requirements
 RoHS6 compliant

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Copyright© 2012 Huawei Technologies Co., Ltd. All Rights Reserved.
THIS DOCUMENT IS FOR INFORMATION PURPOSE ONLY, AND DOES NOT CONSTITUTE ANY KIND OF WARRANTIES.
GDQ33S12B/P
DC-DC Converter Technical Manual V1.7

Designation Explanation
GDQ 33 S 12 B /P
1 2 3 4 5 6
1 — 48Vin, high performance, digital control quarter-brick
2 — Output current: 33 A
3 — Single output
4 — Output voltage: 12 V
5 — With a baseplate
6 — With a PMBus port
Mechanical Diagram
Pin Description
Pin No. Function
1 Vin (+)
2 On/Off
3 Vin (–)
4 Vout (–)
5 Vout (+)
6 SGND
7 SA0
8 PMBus_ALT
9 SA1
10 PMBus_CTL
11 ISHARE
12 PMBus_SCL
13 PMBus_SDA

1. All dimensions in mm [in.]

Tolerances: x.x ± 0.5 mm [x.xx ± 0.02 in.]
x.xx± 0.25 mm [x.xxx ± 0.010 in.]
2. Pin 1-3 are 1.00 ± 0.05 mm [0.040 ± 0.002 in.] diameter
with 2.00 ± 0.10 mm [0.080 ± 0.004 in.] diameter standoff
shoulders.
Pin4 and pin5 are 1.50 ± 0.05 mm [0.060 ± 0.002 in.]
diameter with 2.50 ± 0.10 mm [0.098 ± 0.004 in.] diameter
standoff shoulders.
Pin6 and pin13 are 0.64 ± 0.05 mm [0.025 ± 0.002 in. ]
diameter.
3. M3 Screw used to bolt unit’s baseplate to other surfaces
(such as heatsink) must not exceed 3.00 mm [0.120 in.]
depth below the surface of baseplate.

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GDQ33S12B/P
DC-DC Converter Technical Manual V1.7

Electrical Specifications
Conditions: TA = 25°C (77°F), Airflow = 1.5 m/s (300 LFM), Vin = 48 V, unless otherwise notes.
Parameter Min. Typ. Max. Units Notes & Conditions
Absolute maximum ratings
Input voltage
Continuous - - 80 V -
Transient (100 ms) - - 100 V -

Operating ambient temperature -40 - 85 ºC See the thermal derating curve

Storage temperature -55 - 125 ºC -

Operating humidity - - 95 % RH Non-condensing

Input characteristics
Operating input voltage 36 48 72 V -

Maximum input current - - 14 A Vin= 36 - 72 V; Iout = 33 A

No-load loss - 3 - W Vin= 48 V; Iout = 0 A

Input capacitance 100 220 - µF Electrolytic capacitor

Inrush transient - - 1 A²s -

Input reflected ripple current

- - 200 mA Oscilloscope bandwidth: 20 MHz
(peak to peak)
Output characteristics
Output voltage set point 11.88 12 12.12 V Vin = 48 V; Iout = 16.5 A

Output power 0 - 396 W -

- - ±0.20 % Vin= 40 - 72 V; Iout = 33 A

Output line regulation
- - ±10 % Vin= 36 - 40 V; Iout = 33 A

Output load regulation - - ±3 % Vin = 48 V; Iout = 0 - 33 A

%Vout
Temperature coefficient - - 0.02 TA = -40°C to +85°C (-40°F to +185°F )
/ °C
11.64 - 12.36 V Vin= 40 - 72 V
Output voltage range
10.80 - 12.36 V Vin= 36 - 40 V

External capacitance 470 660 104 µF Electrolytic capacitor (10mΩ< ESR<1Ω)

Output current 0 - 33 A -

Output ripple and noise

- 200 250 mV Oscilloscope bandwidth: 20 MHz
(peak to peak)

Unbalance of current equalization -10 10 % Vin ≥ 38 V; P≥ 300 W

Output voltage Trim range 8.4 - 12 V Adjust the voltage by the PMBus

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GDQ33S12B/P
DC-DC Converter Technical Manual V1.7

Electrical Specifications
Conditions: TA = 25°C (77°F), Airflow = 1.5 m/s (300 LFM), Vin = 48 V, unless otherwise notes.
Parameter Min. Typ. Max. Units Notes & Conditions
Output characteristics

Output voltage overshoot - - 5 % The whole range of Vin , Iout and TA

Output voltage rise time - 50 100 ms 0 - 100%Vout

Output voltage delay time - 50 100 ms Vin - 10%Vout

Switching frequency - 140 - kHz -

Protection characteristics
Input undervoltage protection
Startup threshold 31 34.5 35.5 V -
Shutdown threshold 30 32.5 35 V -
Hysteresis 1 - 4 V -

Output overcurrent protection 36 - 42 A Hiccup mode

Output short circuit protection - - 2 Arms Hiccup mode

Output overvoltage protection 14 - 16 V Hiccup mode

Self-recovery
Overtemperature protection
The values are obtained by measuring the
Threshold 115 125 135 °C temperature of the hottest power
Hysteresis 10 15 20 °C component on the top surface of the
converter

Dynamic characteristics
Current change rate: 0.1 A/µs;
Overshoot amplitude - - 600 mV
Vin= 40 - 72 V;
Recovery time - - 300 µs load : 25% - 50% - 25%; 50% - 75% - 50%

Efficiency
100% load 94.5 95.0 - % Vin = 48 V; Iout = 33 A; TA=25°C (77°F)

50% load 95.5 96.0 - % Vin = 48 V; Iout = 16.5 A; TA = 25°C (77°F)

20% load - 94.0 - % Vin = 48 V; Iout = 6.6 A; TA = 25°C (77°F)

Isolation characteristics
Input-to-output Isolation
- - 1500 V DC Functional Isolation
voltage
Reliability characteristics
Mean time between failures Million Telcordia SR332; 80% load; Airflow = 1.5
- 1.5 - m/s (300 LFM); TA = 40°C (104°F)
(MTBF) hours

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GDQ33S12B/P
DC-DC Converter Technical Manual V1.7

Electrical Specifications
Conditions: TA = 25°C (77°F), Airflow = 1.5 m/s (300 LFM), Vin = 48 V, unless otherwise notes.
Parameter Min. Typ. Max. Units Notes & Conditions
Logic input and output pins in the communications port characteristics
Logic input low level - - 0.8 V -

Logic input high level 2.1 - 3.6 V -

Logic output low level - - 0.25 V IOL= 6mA

Logic output high level 0.6 - 3.6 V IOH= -6mA

PMBus setting-up time 100 - - ns For details about the values of tset and
thold, see "Definition of I2C/PMBus
Setting-up Time and Holding Time"
PMBus holding time 0 - - ns
Other characteristics
Primary On/Off voltage
The low electric level is effective
Low level -0.7 - 1.2 V
High level 2.8 - 8 V
Primary On/Off current
-
Low level - - 1 mA
Secondary CTL voltage
The high electric level is effective
Low level 0 - 0.8 V
High level 2.1 - 3.3 V
Secondary CTL current
-
Low level - - 1 mA
PMBus detected precision

Input voltage detected -1 - 1 V

precision
Output voltage detected - 0.2 - 0.2 V Vin=36 - 72 V; Iout=0 - 33 A;
precision TA = -40°C to +85°C (-40°F to
+185°F )
Output current detected -1 - 1 A
precision
Output power detected -12.56 - 12.56 W
precision
Temperature detected -5 5 ℃ Vin=36 - 72 V; Iout=0 - 33 A;
precision TA = -40°C to +85°C (-40°F to
+185°F )

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DC-DC Converter Technical Manual V1.7

Characteristic Curves

Figure 1: Efficiency (TA = 25°C or 77°F) Figure 2: Power dissipation (TA = 25°C or 77°F)

Figure 3: Thermal derating with airflow from Vin to Figure 4: Thermal derating with airflow from Vin(-)
Vout (Vin = 48 V; Vout = 12 V) to Vin(+) (Vin = 48 V; Vout = 12 V)

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GDQ33S12B/P
DC-DC Converter Technical Manual V1.7

Typical Waveforms

1. During the test of input reflected ripple current, the input terminal must be connected to a 12 µH inductor and a 220 µF
electrolytic capacitor.
2. Point B, which is for testing the output voltage ripple, is 25 mm (0.98 in.) away from the V out(+) pin.
25 mm (0.98 in.) 10 µF
Tantalum
capacitor
12 µH
A B F1
Vin(+) Vout(+)
Vin(+) Vout(+)
Load Load
DC-DC EMI Co1 Co2
converter Cin
filtering On/Off
Vsource S1
Vsource
Vin(–) Vout(–)
Vin(–) Vout(–)

220 µF 220 µF 0.1 µF 660 µF

Electrolytic Electrolytic Ceramic Electrolytic
capacitor capacitor capacitor capacitor

Figure 5: Test set-up diagram Figure 6: Typical circuit applications

F1: 20 A fuse (fast blowing)
Cin: The high-frequency, low equivalent series resistance
(ESR) electrolytic capacitor (220 µF/100 V) is
recommended.
Co1: The 1 µF/25 V ceramic capacitor is recommended.
Co2: The 660 µF tantalum capacitor is recommended.

Is
Vout

Figure 7: Input reflected ripple current Figure 8: Output voltage ripple

(for point A in the test set-up diagram, Vin = 48 V, (for point B in the test set-up diagram, Vin = 48 V,
Vout = 12 V, Iout = 33 A) Vout = 12 V, Iout = 33 A)

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GDQ33S12B/P
DC-DC Converter Technical Manual V1.7

Typical Waveforms
Conditions: TA = 25°C (77°F), Vin = 48 V.

On/Off

On/Off

Vout

Vout

Figure 9: Startup from On/Off Figure 10: Shutdown from On/Off

Vin

Vin
Vout

Vout

Figure 11: Startup by power on Figure 12: Shutdown by power off

Vout Vout

Iout
Iout

Figure 13: Output voltage dynamic response Figure 14: Output voltage dynamic response
(Load : 25% - 50% - 25%, di/dt=0.1 A/µs) (Load : 50% - 75% - 50%, di/dt=0.1 A/µs)

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GDQ33S12B/P
DC-DC Converter Technical Manual V1.7

Remote On/Off Soft-start Power Up

The default output voltage delay time (Vin -
Logic On/Off Pin Level Status
10%Vout) is 50 ms. The default output voltage rise
Enable
time (0 - Vout) is 50 ms. The softstart
Negative Low level On power up of the converter can be reconfigured
logic using the PMBus commands.
High level or left Off
open

On/Off On/Off Pre-Bias Start-up

The converter supports prebias. If the output
terminal has a prebias voltage, the output
Vin(–) Vin(–)
voltage directly increases from the prebias
Simple control Transistor control
voltage to the rated voltage after the converter
starts. The following figure shows the typical
VCC waveform.
On/Off
TTL/ 12 V
COMS On/Off

Vin(–) Vin(–) Vout

Isolation control Direct logic drive
0

Figure 15: Various circuits for driving the On/Off pin Figure 16: Pre-bias

CTL Secondary Enable Control Recommended Fuse

When the On/Off is in low electric level, the The converter has no internal fuse. To meet
PMBus_CTL can perform secondary enable safety and regulatory requirements, a 20 A fuse is
control. recommended.
PMBus_CTL Pin Status
Level
Low level No output The fuse current should be 1.5 to 2 times the maximum
operating current in actual use.
High level or left open Have output

Recommend Reverse Polarity

Output Voltage Adjust using PMBus Protection Circuit
The converter supports online voltage adjustment Reverse polarity protection is recommended
by PMBus commands. The output voltage can be under installation and cabling conditions where
adjusted within the range of 8.4 V to 12.36 V. reverse polarity across the input may occur.

Vin(+) Vin(+)

Software Secondary Enable Control Vin(–) Vin(–)

See the PMBus communications protocol. Figure 17: Recommend reverse polarity
protection circuits

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GDQ33S12B/P
DC-DC Converter Technical Manual V1.7

Input Undervoltage Protection EMC

The converter will shut down after the input For the acceptance standard, see the DC-DC
voltage drops below the undervoltage protection Converter EMC Acceptance Manual.
threshold for shutdown. The converter will start
Vo (+)
to work again after the input voltage reaches the L1 L2 Vin(+)
C1 C2 C3 C4 C5 C6 C7
input undervoltage protection threshold for +
Load
C12
startup. For the Hysteresis, see the Protection Vs
Vin(–)
characteristics. Vo (–)

C8 C9 C10 C11

Output Overcurrent Protection

Figure 18: EMC test set-up diagram
The converter equipped with current limiting
circuitry can provide protection from an output C1, C2, C3, C4, C5: Surface mount device (SMD) ceramic
overload or short circuit condition. If the output capacitor (100 V/1000 nF/X7R/1210)
current exceeds the output overcurrent C6: SMD ceramic capacitor (100 V/100 nF/±10%/X7R/1206)
protection set point, the converter enters hiccup
mode. When the fault condition is removed, the L1, L2: Common-mode inductor (single phase, 473
converter will automatically restart. µH/±25%/14 A/ 1 mm x 25.4 mm x 12.7 mm [0.04 in. x 1.0 in. x
0.5 in.]). The chip component with the same specifications can
also be used.
Output Overvoltage Protection
C8, C9, C10, C11: High-pressure resistant chip ceramic
When the voltage directly across the output pins capacitor (100 nF/1000 V/X7R/2220). meeting the 1 kV
pressure resistance requirement.
exceeds the output overvoltage protection
threshold, the converter will enter hiccup mode. C7: Electrolytic capacitor (100 µF/100 V)
When the fault condition is removed, the
converter will automatically restart. C12: Electrolytic capacitor (660 µF/25 V)

Overtemperature Protection
CE DC PORT CISPR Class B
A temperature sensor on the converter senses
the average temperature of the module. It
protects the converter from being damaged at
high temperatures. When the temperature
exceeds the overtemperature protection
threshold, the output will shut down. It will allow
the converter to turn on again when the
temperature of the sensed location falls by the
value of Overtemperature Protection Hysteresis.

MTBF
Figure 19: EMC test result
The MTBF is calculated according to the
Telcordia, SR332 Method 1 Case3.

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GDQ33S12B/P
DC-DC Converter Technical Manual V1.7

Pin Description PCB Layout Consideration

Pin Description Separate power trace and signal trace to avoid

mutual interferance.
On/Off See "Remote On/Off"
PMBus_SCL PMBus communications port Address Definition
and (connects to the I2C bus)
PMBus_SDA
The resistances of RSA0 and RSA1 are different
PMBus_CTL See "CTL Secondary Enable (resistors with 1% tolerance are recommended).
Control" The SA0 and SA1 pins correspond to different
voltages and numbers. Set an PMBus address by
SA1, SA0, and See "Address Definition" using the formula below. The converter supports
SGND dynamic address detection.
ISHARE and If only one converter is used,
PMBus_ALT leave the two pins open. If
two converters are connected
SA0
parallel, connect ISHARE1 to
RSA0
ISHARE1 and PMBus_ALT to SA1
PMBus_ALT RSA1
SGND

Definition of I2C/PMBus Setting-up

Time and Holding Time Table 2 Address configuration
tset is the duration for which SDA keeps its value
unchanged before SCL increases. RSA0/RSA1 [kΩ] SA0/SA1 [V] SA0 /SA1
thold is the duration for which SDA keeps its value 0 - 15 0 - 0.165 0
unchanged after SCL decreases.
The communication will fail if the time is not 22 0.198 - 0.242 1
consistent with the specifications. 30 0.270 - 0.330 2
51 0.459 - 0.561 3
80.6 0.725 - 0.887 4
113 1.017 - 1.243 5
150 1.350 - 1.650 6
> 220 (including 1.980 - 2.500 7
Parallel Operation left open)

The products can be paralleled if external oring

diodes or oring MOSFETS are used in series
with the output. The PMBus address is determined by the
For further information please contact your local following formula:
sales representative.
PMBusAddress=12 x SA1No. + SA0No.

If two converters are connected in parallel, note the Theoretically, this formula can generate a
following: maximum of 64 PMBus address, but address 0
1. Within 2 seconds after the converters start, the load and address 12 are prohibited.
current must not be less than or equal to 33 A. For details, refer to PMBus Revision 1.0.
2. The address of each converter is unique.

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DC-DC Converter Technical Manual V1.7

PMBus Commands
The products are PMBus compliant. The following table lists the implemented PMBus commands. For
more detailed information see PMBus Power System Management Protocol Specification; Part I – General
Requirements, Transport and Electrical Interface and PMBus Power System Management Protocol; Part II
– Command Language.
Table 3 Common commands

Designation Cmd Impl Designation Cmd Impl

Control Commands Monitoring Commands
OPERATION 01h Yes READ_VIN 88h Yes
CLEAR_FAULTS 03h Yes READ_VOUT 8Bh Yes
STORE_DEFAULT_ALL 11h Yes READ_IOUT 8Ch Yes
RESTORE_DEFAULT_ALL 12h Yes READ_TEMPERATURE_1 8Dh Yes
Output Commands READ_TEMPERATURE_2 8Eh Yes
VOUT_MODE 20h Yes READ_TEMPERATURE_3 8Fh Yes
VOUT_COMMAND 21h Yes READ_DUTY_CYCLE 94h Yes
VOUT_TRIM 22h Yes READ_FREQUENCY 95h Yes
FREQUENCY_SWITCH 33h Yes READ_POUT 96h Yes
Fault Alarm Commands Identification Commands
VOUT_OV_WARN_LIMIT 42h Yes PMBus_REVISION 98h Yes
VOUT_UV_WARN_LIMIT 43h Yes MFR_ID 99h Yes
IOUT_OC_WARN_LIMIT 4Ah Yes MFR_MODEL 9Ah Yes
OT_WARN_LIMIT 51h Yes MFR_REVISION 9Bh Yes
VIN_OV_WARN_LIMIT 57h Yes MFR_LOCATION 9Ch Yes
VIN_UV_WARN_LIMIT 58h Yes MFR_DATE 9Dh Yes
Time Sequence Setting Commands Customized Commands
TON_DELAY 60h Yes MFR_SOFT_VERSION F3h Yes
TON_RISE 61h Yes PMBus_CMD_MFR_ISHA F8h Yes
Status Commands RE_ENABLE

STATUS_BYTE 78h Yes PMBus_CMD_MFR_BAR FAh Yes

CODE_FIRSTHALF
STATUS_WORD 79h Yes
PMBus_CMD_MFR_BAR FBh Yes
STATUS_VOUT 7Ah Yes CODE_SECONDHALF
STATUS_IOUT 7Bh Yes
STATUS_INPUT 7Ch Yes
STATUS_TEMPERATURE 7Dh Yes
1. Cmd is short for Command.
STATUS_CML 7Eh Yes 2. Impl is short for Implemented.

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GDQ33S12B/P
DC-DC Converter Technical Manual V1.7

Qualification Testing

Parameter Units Condition

High Accelerated Life Lowest operating temperature: -60°C ( -76°F); highest operating
4
Test (HALT) temperature: 110°C (230°F); vibration limit: 40 G
Proof Of Screen (POS) 4 80 temperature cycles; 50% vibration limit stress: 20 G
High Accelerated
8 4 temperature cycles; 50% vibration limit stress: 20 G
Stress Audit (HASA)
500 temperature cycles between -40°C (-40°F) and +125°C (+257°F)
Thermal Shock 32 with the temperature change rate of 20°C (68°F) per minute
Lasting for 30 minutes both at -40°C (-40°F) and +125°C (+257°F)
Temperature Humidity 85°C (185°F); 85% RH; 1000 operating hours under lowest load
16
Bias power
High Temperature Rated input voltage; 55°C (131°F); 1000 operating hours under 50%
16
Operation Life (HTOL) - 80% load power

Thermal Consideration

Thermal Test Point Power Dissipation

Sufficient airflow should be provided to ensure The converter power dissipation is calculated
reliable operating of the converter. Therefore, based on efficiency. The following formula
thermal components are mounted on the top reflects the relationship between the consumed
surface of the converter to dissipate heat to the power (Pd), efficiency (ŋ), and output power
surrounding environment by conduction, (Po): Pd=Po(1-η)/η
convection and radiation. Proper airflow can be
verified by measuring the temperature at the
thermal test point. Thermal Testing Setup
Test board: D x W=254mm x 254mm, 2oz, 4
Thermal test point layers, cross section of the wind tunnel: 800mm
x 45mm.

Spacing board Test board

Test sample

Figure 20: Thermal test point

Airflow and
temperature sensor
Airflow

The temperature at the thermal test point on the converter

can not exceed 105°C (221°F). Otherwise, the converter
will be protected against overtemperature and will not
operate properly. Figure 21: Wind tunnel test setup

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GDQ33S12B/P
DC-DC Converter Technical Manual V1.7

Mechanical Consideration
Installation
Although the converter can be mounted in any direction, free airflow must be taken.

Soldering
The converter is compatible with standard wave soldering techniques. When wave soldering, the
converter pins should be preheated for 20 - 30 seconds at 110°C (230°F) , and wave soldered at 260°C
(500°F) for less than 10 seconds.
When hand soldering, the iron temperature should be maintained at 425°C (797°F) and applied to the
converter pins for less than 5 seconds.
The converter can be rinsed using the isopropyl alcohol (IPA) solvent or other proper solvents.

HUAWEI TECHNOLOGIES CO., LTD.

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Shenzhen 518129
People's Republic of China
www.huawei.com

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