jw1231 datasheet r0.84 en 20150211 · 2020. 2. 20. · 2) the bm2232 guarantees robust performance...

Parameters Subject to ChangeParameters Subject to ChangeParameters Subject to ChangeParameters Subject to Change Without NoticeWithout NoticeWithout NoticeWithout Notice

1

DESCRIPTION

BM2232 removes the 100/120Hz current ripple in

a LED string.

BM2232 allows user to setup the maximum LED

cathode voltage via a resistor divider. BM2232

provides voltage limit threshold and short

threshold for protection. If the voltage on LED pin

exceeds voltage limit threshold, the current ripple

removing function is disabled to minimize power

dissipation in the chip. The LED string is

considered short when LED pin voltage is higher

than short threshold for over 0.5 second. The

internal MOSFET shuts down when LED is

shorted.

BM2232 also provides HOT-PLUG protection.

The maximum LED current is internally limited to

0.7A.

BM2232 has over temperature protection (OTP).

When OTP is trigged, the current ripple removing

function is disabled until system restarts.

FEATURES

� Adaptive 100/120Hz current ripple remover

� Input voltage range 5V~60V

� Built-in 60V power MOSFET

� LED voltage low to 0.4V when LED current is

0.35A

� Programmable LED current ripple

� Programmable maximum LED cathode

voltage

� Internal LED current limitation

� Short LED protection

� Hot plug protection

� Over temperature protection

� ESOP8 Package

APPLICATIONS

� LED lighting

TYPICAL APPLICATION

DATASHEET

BM2232

Adaptive 100/120Hz Current Ripple RemoverMax Input Current ≤0.5A

Bright Moon Semiconductor BM2232

2

ORDER INFORMATION

PIN CONFIGURATION

TOP VIEW

ESOP8

ABSOLUTE MAXIMUM RATING1111））））

VIN PIN ................................................................................................................................................ 60V

LED PIN ..............................................................................................................................-0.3V to 60V

VC, VLMT ...............................................................................................................................-0.3V to 6V

Junction Temperature2)3)................................................................................................................... 150ºC

Lead Temperature ................... ........................................................................................................ 260ºC

Storage Temperature........................................................................................................ -65ºC to +150ºC

RECOMMENDED OPERATING CONDITIONS

VIN............................................................................................................................................4.7V to 55V

LED pin ........................................................................................................................................... <60V

Junction Temperature (TJ)....................................................................................................-40ºC to 125ºC

THERMAL PERFORMANCE4444）））） θθθθJA JA JA JA θθθθJcJcJcJc

ESOP8 .............................................................................................................................50.......10ºC/W Note：：：：

1) Exceeding these ratings may damage the device.

2) The BM2232 guarantees robust performance from -40°C to 150°C junction temperature. The junction temperature

range specification is assured by design, characterization and correlation with statistical process controls.

3) The BM2232 includes thermal protection that is inte nded to protect the device in overload conditions. Thermal

protection is active when junction temperature exceeds the maximum operating junction temperature. Continuous

operation over the specified absolute maximum operating junction temperature may damage the device.

4) Measured on JESD51-7, 4-layer PCB.

LEAD FREE FINISH TAPE AND REEL PACKAGE TOP

MARKING BM2232ESOP#PBF BM2232ESOP#TRPBF ESOP8 BM2232


BM2232 Adaptive 100/120Hz Current Ripple Remover (Max 0.5A)

3

ELECTRICAL CHARACTERISTICS

VIN = 12V, TA = 25ºC, unless otherwise stated.

Item Symbol Condition Min. Typ. Max. Units

VIN Start Up Voltage Threshold VIN_ON 3.9 4.2 4.5 V

VIN Operation Current IIN ILED=500mA， VIN=50V 0.12 0.20 0.34 mA

LED Voltage Limit Threshold VTH_VLMT 0.9 1 1.1 V

LED Short Protection Threshold VTH_SHORT 1.8 2 2.2 V

LED Short Protection Delay TSP 0.35 0.5 0.65 s

LED Open Protection Threshold ITH_OPEN 50 mA

LED Open Protection Delay TOP 0.35 0.5 0.65 s

Regulated LED Pin Voltage VLEDR ILED=500mA 0.25 0.40 0.65 V

LED Current Limit ICLMT 0.5 0.7 1.6 A

Over Temperature Protection Threshold OTP 125 135 145 ℃

PIN DESCRIPTION

Pin No. Name Description

1 NC No Connection

2 LED

Connect to Cathode of LED string 3 LED

4 LED

5 VLMT Resistor Divider to Setup LED Voltage Limit

6 VC Capacitor to Program LED Current Ripple

7 GND Power Ground

8 VIN Power Supply

0

(exposed PAD) GND Power Ground



4

TYPICAL PERFORMANCE CHARACTERISTICS

Note：：：：The pre-driver is 1600 18W T8 program. The output specification is 40V/460mA with electrolytic

capacitor 330uF/63V * 2. The VO noted in the figure is the pre-driver LED voltage, ILED is the output current, VC is

the 2232 VC pin voltage and V LED- is the 2232 LED pin voltage. LEDLEDLEDLED currentcurrentcurrentcurrent (VIN=220V,Io=(VIN=220V,Io=(VIN=220V,Io=(VIN=220V,Io=460460460460mAmAmAmA,,,,Vo=Vo=Vo=Vo=44440V,0V,0V,0V, electrolytic capacitor electrolytic capacitor electrolytic capacitor electrolytic capacitor 330330330330uF/uF/uF/uF/63636363V*2V*2V*2V*2)))) current ripple:current ripple:current ripple:current ripple:330330330330mA,7mA,7mA,7mA,72222%%%%

LED LED LED LED currentcurrentcurrentcurrent witwitwit (VIN=220V,Io=(VIN=220V,Io=(VIN=220V,Io=(VIN=220V,Io=464646460mA0mA0mA0mA,,,,Vo=Vo=Vo=Vo=44440V,0V,0V,0V, electrolytic capacitor electrolytic capacitor electrolytic capacitor electrolytic capacitor 330330330330uF/uF/uF/uF/63636363V*2V*2V*2V*2)))) current ripple:current ripple:current ripple:current ripple:18181818mA,mA,mA,mA,4444%%%%

SSSSystem ystem ystem ystem EEEEfficiency comparison with and fficiency comparison with and fficiency comparison with and fficiency comparison with and (VIN=220V,Io=(VIN=220V,Io=(VIN=220V,Io=(VIN=220V,Io=464646460mA0mA0mA0mA,,,,Vo=Vo=Vo=Vo=44440V,0V,0V,0V, electrolytic capacitor electrolytic capacitor electrolytic capacitor electrolytic capacitor 330330330330uF/uF/uF/uF/63636363V*2V*2V*2V*2)))) LED LED LED LED Open Open Open Open testtesttesttest

LED Short testLED Short testLED Short testLED Short test

PrePrePrePre----driverdriverdriverdriver output capacitor short testoutput capacitor short testoutput capacitor short testoutput capacitor short test

LEDLEDLEDLED hot plug testhot plug testhot plug testhot plug test

CCCContinuous power on/off testontinuous power on/off testontinuous power on/off testontinuous power on/off test



5

FUNCTIONAL DESCRIPTION

BM2232 removes the 100/120Hz LED current

ripple in LED string (≤60V).

Operation

The LED string and BM2232 are both supplied by

an AC/DC current source. The LED pin is

connected to the cathode of LED string. BM2232

transfers the LED current ripple to voltage ripple

on chip, and ensures constant voltage across

LED string and constant current flow through LED

string.

BM2232 minimizes LED cathode voltage to

improve system efficiency.

Current Ripple Removing

The Capacitor between VC and GND should be

large enough to remove the LED current ripple.

However, too large capacitor may slow down the

dynamic response.

LED Pin Voltage Limit

The voltage ripple on LED pin increases when the

current ripple is removed, which increases power

dissipation on chip. The resistor divider

connected between LED and GND sets LED PIN

voltage limit.

The limit threshold is calculated as below:

VLIMIT= 1V * (RLMT1+RLMT2)/RLMT2

LED Current Limit

The LED current is limited at 0.7A internally. The

current limit protects the chip from short LED or

HOT-PLUG.

The function of current limit has higher priority

than LED Pin voltage limit. LED pin voltage limit

function is disabled when LED current exceed

0.7A.

LED Short Protection

When the VLMT Pin voltage exceeds 2V for more

than 0.5 second, BM2232 considers the LED

string SHORT.

BM2232 latches OFF the internal MOSFET until

system restart.

HOT-PLUG Protection

A LED string is considered open, when the LED

current is lower than 50mA for more than 0.5

second. BM2232 shuts down the internal

MOSFET during open LED.

If a LED string is connected suddenly during the

OPEN state, the voltage on LED PIN can rise

rapidly and exceed the LED PIN voltage limit

threshold. Then the OPEN state will be reset,

internal MOSFET will be turned on and the LED

current is limited to 0.7A.



BM2232

6

Over Temperature Protection

BM2232 enters Over Temperature Protection

when the chip temperature exceeds 140℃. The

current ripple removing function is disabled during

OPT. OPT can only be reset when system

restarts.

PCB Design Guideline

1. The VIN bypass capacitor should be placed

as close as possible between the VIN pin and

GND pin.

2. BM2232 should be placed far away from the

power devices such as MOSFET and SBD.

3. The LED current loop should be as small as

possible.



7

APPLICATION INFORMATION

BM2232 design guide:

1. Design considerations:

a) The maximum voltage rating of LED

pin is 60V, so the overvoltage

threshold of the pre-driver must be

lower than 60V in order to protect the

chip in LED short condition.

b) A LED string should be used to test the

characteristics of BM2232 including

open and short circuit test.

2. The recommended operating current of

BM2232 is 400mA (max 700mA). The power

loss and temperature rise of the chip

depend on the amplitude of the output

voltage ripple and LED current.

3. Based on the power factor correction of the

pre-driver, the law of energy conservation

and reasonable temperature rise of the

BM2232, the output capacitance of the

pre-driver can be approximately calculated

as follows:

PIN: Input power

POUT: Output power

PD: Power loss of BM2232

ILED: LED current

U: Output voltage

VMIN: the minimum LED pin voltage △U: Peak to peak output voltage ripple

VLED-: LED- pin voltage

T: line cycle

η: Efficiency of the system

a) The power factor correction of the

pre-driver and the law of energy

conservation:

t

EPIN

P

T/8

KKKKKKKK①

KKKKKKKK②

b) The energy formula of capacitance:

KKKKKKKK③

c) The reasonable temperature rise of the

BM2232

KKKKKKKK④

KKKKKKKK⑤

KKKKKKKK⑥

d) The smaller output power, the larger

capacitance is needed as it can be

seen in the equation above.

e) For example :

i.Given ：PD=0.5W (Equivalent to 40℃

temperature rise); η=0.85; f=1/T=50Hz

Then,

The result shows in the following figure:



8

ii. Given ：PD=0.8W (Equivalent to 64℃

temperature rise); η=0.85; f=1/T=50Hz

Then the result shows in the below:

4. BM2232 allows user to setup the maximum

LED cathode voltage via a resistor divider.

Resistors of 400K & 100K are

recommended.

5. The capacitance between VC and GND

determines the final current ripple. It should

be large enough to remove the LED current

ripple. However, too large capacitor may

slow down the dynamic response.

1uF or 2.2uF is recommended.



9

REFERENCE DESIGN

Reference 1：：：：


BM2232 Adaptive 100/120Hz Current Ripple Remover (Max 0.5A)BM2232 Adaptive 100/120Hz Current Ripple Remover (Max 0.5A)

BM2232

10

PACKAGE OUTLINE

ESOP8 unit: mm



jw1231 datasheet r0.84 en 20150211 · 2020. 2. 20. · 2) the bm2232 guarantees robust performance...

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