BD83A44EFV-M BD83A44MUF-M
Description of Blocks
Unless otherwise stated, the value in the sentence is the typical value.
1 VREF
Internal reference voltage circuit. By setting the EN pin to High, 5 V is generated and output to the REG pin. REG voltage
is used as the power supply for the internal circuit. Also, this is used to fix each input pin to High voltage outside the IC.
Connect REG capacitance (CREG = 2.2 μF) to the REG pin for the phase compensation. Note that if CREG is not connected,
unstable operation such as oscillation will occur.
2 LDSW Driver
Input overcurrent protection circuit. If the voltage between the VCC-CSH pin is 0.1 V or more and continues for 10 μs or
more, the input overcurrent protection is activated, and the load switch (M1) is latched OFF as LDSW pin voltage = VCC
pin voltage. When the input overcurrent protection is detected, the FAIL pin goes Low. A 3 MΩ resistor is connected inside
the IC between the VCC-LDSW pin. Do not connect a resistor between the VCC-LDSW pin because connecting a resistor
between the VCC-LDSW pin outside the IC may prevent the load switch from being turned ON.
When the VCC pin voltage is turned ON setting the EN pin to Low, the voltage between the VCC-LDSW pin may open
momentarily and an inrush current may flow depending on the VCC startup speed and the type of load switch used. Be
sure to check with the actual application.
3 OSC (Oscillator)
Oscillation frequency generator. DC/DC oscillation frequency (fOSC) can be set by connecting a resistor for oscillation
frequency setting (RRT) between the RT pin and ground. In addition, DC/DC oscillation frequency can be externally
synchronized by inputting the external synchronization frequency (fSYNC) to the SYNC pin.
4 SSCG (Spread Spectrum Clock Generator)
Spread spectrum circuit. The spread spectrum function (SSCG) is activated by shorting the SYNC pin and the REG pin.
Noise peaks can be reduced by periodically changing the oscillation frequency by SSCG. The fluctuation range of the
frequency due to SSCG is from 100 % to 92 % of the set oscillation frequency. The oscillation frequency fluctuation period
is 2.3 kHz.
5 SLOPE
This circuit generates a saw wave that serves as the source of the switching pulse of DC/DC converter. SLOPE output
signal and COMP pin voltage are compared, and a switching pulse is generated.
6 Minimum Channel Selector
Selector circuit for detecting LED pin voltages. Selects the lowest pin voltage among LED1 to LED4 pin voltages and inputs
it in Error AMP.
7 Error AMP (Error Amplifier)
This is an error amplifier that takes LED control voltage and the smallest value of the LED1 to LED4 pin voltages as input.
Phase compensation can be set by connecting a resistor and a capacitor to the COMP pin.
8 Soft Start
Soft start circuit for DC/DC converters. This function is used to suppress a steep increase in the inductor current at startup
and an overshoot in the output voltage. Controls the change in switching Duty by limiting the rising edge of the output of
Error AMP (COMP pin voltage) with the soft start function.
9 PWM COMP (PWM Comparator)
This comparator compares COMP pin voltage, which is the output of Error AMP, with SLOPE output signal. Controls the
Duty of the switching pulse of DC/DC converter.
10 Additional Pulse
This circuit adds switching pulses of DC/DC converter. With the pulse addition function, the LED current can be supplied
stably even when the PWM dimming ratio decreases.
11 DC/DC Control LOGIC
This circuit generates the logic of the built-in Low side FET for boost output from the SW pin.
12 Low side FET / Pre Driver
Built-in Low side FET for boost output from the SW pin and its driving circuit.
www.rohm.com
TSZ02201-0T2T0B200460-1-2
© 2022 ROHM Co., Ltd. All rights reserved.
6/47
TSZ22111 • 15 • 001
08.May.2023 Rev.001
5秒后页面跳转
电子元器件中的网络滤波器、EMI滤波器与EMC滤波器：分类关系与功能详解
NTC热敏电阻与PTC热敏电阻的应用原理及应用范围
GTO与普通晶闸管相比为什么可以自关断？为什么普通晶闸管不能呢？从GTO原理、应用范围带你了解原因及推荐型号
LF353数据手册解读：特性、应用、封装、引脚说明、电气参数及替换型号推荐
微信公众号
抖音公众号
浙公网安备 33010502006866号 浙ICP备10014259号-119
营业执照ICP证
数据手册
如果您发现信息不准确，
