IS31FL3198A

3-LED DRIVER WITH CHARGE PUMP

Preliminary Information
August 2024

GENERAL DESCRIPTION FEATURES

The IS31FL3198A is a compact and efficient 3-channel  3.3V±5% supply voltage
charge pump LED driver. It is capable of driving 1 to 3  Maximum output current of OUT_X: 80mA,
LEDs with a low drop-out and current matching so all 3 adjustment external resister: 22mA ~ 80mA
LEDs maintain consistent brightness. Each channel - 3 channel independent ON/OFF control
can support up to 80mA of current. The current of each - Current setting in eight steps
channel can be adjusted by the setting of current
resistor and the control.  Charge pump
- 2x operating mode
The built−in charge pump (CP) structure will
automatically toggle 2x operations. This DC/DC - ≥ 6.27V CPOUT voltage to support LED
converter operates at a high switching frequency which (LED VF≤ 4.8V)
enables the use of small external capacitors. The  ISET pin short protection
IS31FL3198A is shutdown consuming less than 1µA.  Current mismatch (channel to channel): ±3%
The IS31FL3198A is available in a small QFN-16  Current accuracy (device to device): ±6%
(3mm×3mm) package. It operates at 3.3V over the  LED Current rising time
temperature range of -40°C to +125°C. - 0.5μs Typ. (IOUT ×90%)
- 1μs Max. (IOUT ×90%)
 LED Current falling time
- 0.5μs Typ. (IOUT ×10%)
- 1μs Max. (IOUT ×10%)
 QFN-16 (3mm×3mm) package
 Operating temperature range is -40°C ~ +125°C
 RoHS & Halogen-Free Compliance
 TSCA Compliance
APPLICATIONS
 CIS module

TYPICAL APPLICATION CIRCUIT

3.3V
1 15
VCC CP 1μF
16
1μF CN

5
EN_B EN_B 13
6 CPOUT
EN_G EN_G
7 1μF
EN_R EN_R
4 IS31FL3198A
EN EN
3 12
SDB SDB OUT_R
2 10
ISET OUT_G
RISET
8
4.7kΩ 9,11 OUT_B
GND
14

Figure 1 Typical Application Circuit

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Rev. 0A, 08/19/2024
IS31FL3198A
PIN CONFIGURATION
Package Pin Configuration (Top View)

13 CPOUT
14 GND
16 CN
15 CP
VCC 1 12 OUT_R
ISET 2 11 GND
QFN-16
SDB 3 10 OUT_G
EN 4 9 GND

EN_B 5
EN_G 6
EN_R 7
OUT_B 8
PIN DESCRIPTION
No. Pin Description
1 VCC Power supply
2 ISET LED current setting pin
Pull below 0.4V to activate low power shutdown mode.
3 SDB
H: normal operation mode, L: shut down mode
Outputs current enable pin.
4 EN
H: outputs enable, L: outputs disable
5 EN_B OUT_B enable pin, H: OUT_B enable, L: OUT_B disable
6 EN_G OUT_G enable pin, H: OUT_G enable, L: OUT_G disable
7 EN_R OUT_R enable pin, H: OUT_R enable, L: OUT_R disable
8 OUT_B Output pin, blue channel
9, 11, 14 GND GND
10 OUT_G Output pin, green channel
12 OUT_R Output pin, red channel
Charge pump power supply output pin to drive load circuits, requires 1μF
13 CPOUT
capacitor connected between this pin and ground pin.
15 CP Charge pump flying capacitor positive terminal. (Note 1)
16 CN Charge pump flying capacitor negative terminal. (Note 1)
Thermal Pad Connect to GND.
Note 1: The flying capacitors should be placed as close as possible to the IC and the signal trace between the capacitor and CP terminals keep
as short as possible.

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IS31FL3198A
ORDERING INFORMATION
Industrial Range: -40°C to +125°C
Order Part No. Package QTY/Reel

IS31FL3198A-QFLS4-TR QFN-16, Lead-free 2500

Copyright © 2024 Lumissil Microsystems. All rights reserved. Lumissil Microsystems reserves the right to make changes to this specification and its products
at any time without notice. Lumissil Microsystems assumes no liability arising out of the application or use of any information, products or services described
herein. Customers are advised to obtain the latest version of this device specification before relying on any published information and before placing orders
for products.
Lumissil Microsystems does not recommend the use of any of its products in life support applications where the failure or malfunction of the product can
reasonably be expected to cause failure of the life support system or to significantly affect its safety or effectiveness. Products are not authorized for use in
such applications unless Lumissil Microsystems receives written assurance to its satisfaction, that:
a.) the risk of injury or damage has been minimized;
b.) the user assume all such risks; and
c.) potential liability of Lumissil Microsystems is adequately protected under the circumstances

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IS31FL3198A
ABSOLUTE MAXIMUM RATINGS (NOTE 2)
Supply voltage, VCC -0.3V ~ +6.0V
Voltage at CPOUT -0.3V ~ +7.5V (Note 3)
Voltage at any input pin -0.3V ~ VCC+0.3V
Maximum junction temperature, TJMAX +150°C
Operating temperature range, TA=TJ -40°C ~ +125°C
Storage temperature range, TSTG -65°C ~ +150°C
Package thermal resistance, junction to ambient (4-layer standard test PCB
56.5°C/W
based on JESD 51-2A standard), θJA
ESD (HBM) ±TBDkV
ESD (CDM) ±TBDV
Note 2: Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings
only and functional operation of the device at these or any other condition beyond those indicated in the operational sections of the specifications
is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
Note 3: If CPOUT is higher than 7.5V (Typ.), IC will disable the charge pump function. If CPOUT is lower than 7.0V (Typ.), IC will enable the
charge pump function again.

ELECTRICAL CHARACTERISTICS
The following specifications apply for VCC= 3.3V, TA= 25°C, unless otherwise noted.
Symbol Parameter Condition Min. Typ. Max. Unit
VCC Supply voltage 3.135 3.3 3.465 V
ICC Quiescent operating current 2x mode, all outputs disable 2.5 3.5 mA
ISD Shutdown current VSDB= 0V 0.5 1 µA
VCPOUT Voltage of CPOUT LED current= 0mA 6.27 6.6 6.93 V
RISET= 4.7kΩ±1%, VOUT_X= 3.5V (Note 4) 62 66 70 mA
IOUT Output current of R/G/B
RISET= 3.9kΩ±1%, VOUT_X= 3.5V (Note 4) 79.5 mA
RISET< 1.45kΩ,
IPT LED protect current 105 150 217.5 mA
Quit the protection when RISET> 3kΩ
IMAT Current matching RISET= 4.7kΩ±1%, VOUT_X= 3.5V -3 3 %
IACC Current accuracy RISET= 4.7kΩ±1%, VOUT_X= 3.5V -6 6 %
VHR Current sink headroom IOUT= 66mA 250 350 mV
VF LED forward voltage (Note 5) 1.1 4.8 V
EN_R, G, B= “000” 100
EN_R, G, B= “001” 87.5
EN_R, G, B= “010” 75
EN_R, G, B= “011” 62.5
ILED LED current VOUT_x= 3.5V %
EN_R, G, B= “100” 50
EN_R, G, B= “101” 37.5
EN_R, G, B= “110” 25
EN_R, G, B= “111” 12.5
TSD Thermal shutdown (Note 6) 166 °C
TSD_HY Thermal shutdown hysteresis (Note 6) 24 °C

Charge Pump Characteristics

tR_CPOUT CPOUT rise time CCPOUT= 1µF, CCPCN= 1µF 1 ms
CCPOUT= 1µF, CCPCN= 1µF (Note 6)
tF_CPOUT CPOUT fall time 20 ms
Time VCPOUT= 6.6V to VCPOUT= 3.3V

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IS31FL3198A
ELECTRICAL CHARACTERISTICS (CONTINUED)
The following specifications apply for VCC= 3.3V, TA= 25°C, unless otherwise noted.
Symbol Parameter Condition Min. Typ. Max. Unit
Charge pump operating
fCLK 1000 kHz
frequency
Logic Electrical Characteristics (SDB, EN, EN_R, G, B)
VIL Logic “0” input voltage VCC = 3.135V~3.465V 0 0.3VCC V
VIH Logic “1” input voltage VCC = 3.135V~3.465V 0.7VCC VCC V
IIL Logic “0” input current VINPUT = 0V (Note 6) 5 nA
IIH Logic “1” input current VINPUT = VIO (Note 6) 5 nA

SDB Switch Characteristics

tON LED current on time (Note 7) 0.5 1 µs
tOFF LED current off time (Note 7) 0.5 1 µs
tSU Reset valid setup time EN_R/G/B to EN (Note 7) 1 µs
tHD Count up setup time EN to EN_R/G/B (Note 7) 1 µs
tCL Current set clean time (Note 7) 1 µs
tSDB1 Shutdown period 1 (Note 8) 150 ns
tSDB2 Shutdown period 2 (Note 8) 150 ns
tSTUP Startup time (Note 8) 1 ms
Note 4: IOUT＝ 66×4.7kΩ/RISET, recommend minimum RISET value is 3.9kΩ (IOUT= 79.5mA).
Note 5: Set a lower limit value 1.1V only 1 of 3 channels and the other 2 channels low limit is 2V.
Note 6: Guaranteed by design.
Note 7:

0.7VCC
EN 0.3VCC
tSU tHD
0.7VCC 0.7VCC
EN_R/G/B
High Setting
tCL tCL
tHD
EN_R/G/B
Low Setting 0.3VCC tON

90%

OUT Current 10%

tOFF

Note 8: SDB and EN pin should keep low when turning on the VCC.

tSDB1

3.135V
VCC
tSTUP tSDB2

SDB

EN

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IS31FL3198A
FUNCTIONAL BLOCK DIAGRAM
ISET VCC

8 Steps
SDB Current ISET POR OSC BG 2xCP CP
Setting
OT CN
ISET CPOUT_OVP
VCC_OVP
CLAMP CPOUT
IREF <3:1> RISET <2.1k to SD OUT

EN
OUT_B
Control Logic B
EN_B
OUT_G
Control Logic G
EN_G
OUT_R
Control Logic R
EN_R OUTPUT
GND

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Rev. 0A, 08/19/2024
IS31FL3198A
TYPICAL APPLICATION INFORMATION

GENERAL DESCRIPTION A bypass capacitor on the incoming supply will reduce

its AC impedance and the impact of the charge pump
The IS31FL3198A include the charge pump power
switching noise. A 1µF bypass capacitor is sufficient.
supply and 3 channels LED driver who drives the LED
of the anode common in the constant current. The ISET MAXIMUM OUTPUT CURRENT
current to pass for each channel can be adjusted by
The maximum output current of OUT1~OUT3 can be
the external resistance and the control signals’ setting.
adjusted by the external resistor, RISET, as described
Also, it has the control pins which turn on or off the
in Formula (2).
current.
66
The IS31FL3198A LED driver integrates a switched IOUT = ×4.7kΩ 2
capacitor charge pump to power three LEDs with a RISET
programmable regulated current, up to 80mA (Max.) The recommended value of RISET is 4.7kΩ (IOUT=
per channel. It only requires four external components: 66mA).
supply decoupling capacitor, an output bypass
capacitor, a flying capacitors and a RISET resistor. The recommended minimum value of RISET is 3.9kΩ
(IOUT= 79.54mA).
Upon power up, the built-in charge pump converter
will initialize in the 2x mode. The IS31FL3198A will The recommended maximum value of RISET is 14kΩ
remain in this mode always. (IOUT= 22.16mA).

The current delivered through the LED load is The current setting can be set to 8 levels with
controlled by an internal configurable low dropout EN_R/G/B and EN combination.
current source. The current level is set by the levels by latch the
CHARGE PUMP pattern of EN_R, EN_G, EN_B at the time of following
EN rise to decide the current value. After the EN_R,
The converter is based on a 2-stage charge pump EN_G, EN_B signal fall once, the current interlocks
technique to efficiently generate a DC voltage to with EN_R, EN_G, EN_B’s on or off.
supply the RGB LED current.
EN=H
The integrated capacitive charge pump is designed
EN EN=L Turn on RGB
for CPOUT = VCC × 2. The charge pump converter
only needs three external components: supply EN_R Not turn on
decoupling capacitor, output bypass capacitor and
flying capacitors. EN_G

To maintain the lowest output resistance, use

EN_B
capacitors with low ESR. The charge-pump output
resistance is a function of CP and COUT’s ESR and After EN_X fall, LED is on when EN and EN_X both high
the internal switch resistance. Minimizing the charge-
pump capacitor’s ESR minimizes the total resistance. Figure 2 EN Control

Using a larger flying capacitor (CP) reduces the The relation between the pattern and the current
output impedance and improves efficiency however, setting value of EN_R, EN_G, EN_B at the time of
above a certain point, increasing CP’s capacitance the EN rise as follows.
has a negligible effect because the output resistance
becomes dominated by the internal switch resistance EN_R EN_G EN_B Current Setting
and capacitor ESR. But when space is a constraint, it
may be necessary to sacrifice low output resistance 0 0 0 100%
for the sake of small capacitor size. 0 0 1 87.5%
Increasing the output capacitance (COUT) reduces the 0 1 0 75%
output ripple voltage. Decreasing its ESR reduces
both output resistance and ripple. Smaller 0 1 1 62.5%
capacitance values can be used with light loads. Use 1 0 0 50%
the following equation to calculate the peak-to-peak
ripple: 1 0 1 37.5%
VRIPPLE = IOUT/(fOSC×COUT) + 2×IOUT×ESRCOUT (1) 1 1 0 25%
1 1 1 12.5%

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IS31FL3198A
SHUTDOWN MODE
Shutdown mode can either be used as a means of
reducing power consumption or generating a flashing
display (repeatedly entering and leaving shutdown
mode).
The chip enters hardware shutdown when the SDB
pin is pulled low, wherein it consumes only 0.5μA
(Typ.) current.

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IS31FL3198A
CLASSIFICATION REFLOW PROFILES
Profile Feature Pb-Free Assembly

Preheat & Soak

150°C
Temperature min (Tsmin)
200°C
Temperature max (Tsmax)
60-120 seconds
Time (Tsmin to Tsmax) (ts)
Average ramp-up rate (Tsmax to Tp) 3°C/second max.
Liquidous temperature (TL) 217°C
Time at liquidous (tL) 60-150 seconds
Peak package body temperature (Tp)* Max 260°C
Time (tp)** within 5°C of the specified
Max 30 seconds
classification temperature (Tc)
Average ramp-down rate (Tp to Tsmax) 6°C/second max.
Time 25°C to peak temperature 8 minutes max.

Figure 3 Classification Profile

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Rev. 0A, 08/19/2024
IS31FL3198A
PACKAGE INFORMATION

QFN-16


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Rev. 0A, 08/19/2024
IS31FL3198A
RECOMMENDED LAND PATTERN

QFN-16

Note:
1. Land pattern complies to IPC-7351.
2. All dimensions in MM.
3. This document (including dimensions, notes & specs) is a recommendation based on typical circuit board manufacturing parameters. Since
land pattern design depends on many factors unknown (eg. User’s board manufacturing specs), user must determine suitability for use.

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Rev. 0A, 08/19/2024
IS31FL3198A
REVISION HISTORY
Revision Detail Information Date
0A Initial relesae 2024.08.19

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Rev. 0A, 08/19/2024