PWM 脉宽调制 芯片求解

请问哪位知道 pwm芯片的具体使用方法呀？[PWM应该是数字输入调制脉冲输出的吧！？]

我看了DRV104的英文资料，由于水平有限我发现这货怎么是模拟输入
DRV104资料管脚说明中，第一脚就说是用1.3—3.9V电压来控制输出脉冲的占空比；第三脚是说用电压来控制调制输出脉冲的频率的；最后一个管脚虽是TTL电平输入，但如果是最后这个脚串行数字输入的话，资料中也并未提及其串行输入的时序控制图；

难道这个芯片是模拟输入调制脉冲输出吗？PWM应该是数字输入调制脉冲输出的吧！？难道是我把PWM 的原理理解错了吗？

求解（不拘泥于此型号芯片，哪位知道其他PWM芯片使用方法和原理的也请多指教）

DRV104管脚说明 如下：（附件：DRV104的英文资料）
PIN NAME DESCRIPTION
1 Duty Cycle Adjust Internally, this pin connects to the input of a comparator and a (2.75 x IREF) current source from VS. The voltage at this node linearly
sets the duty cycle. The duty cycle can be programmed with a resistor, analog voltage, or the voltage output of a D/A converter. The
active voltage range is from 1.3V to 3.9V to facilitate the use of single-supply control electronics. At 3.56V, the output duty cycle is
near 90%. At 1.5V, the output duty cycle is near 10%. Internally, this pin is forced to 1.24V. No connection is required when the device
is in slave mode.
2 Delay Adjust This pin sets the duration of the initial 100% duty cycle before the output goes into PWM mode. Leaving this pin floating results in
a delay of approximately 18μs, which is internally limited by parasitic capacitance. Minimum delay may be reduced to less than 3μs
by tying the pin to 5V. This pin connects internally to a 15μA current source from VS and to a 2.6V threshold comparator. When the
pin voltage is below 2.6V, the output device is 100% On. The PWM oscillator is not synchronized to the Input (pin 1), so the duration
of the first pulse may be any portion of the programmed duty cycle. No connection is required when the device is in slave mode.
3 Oscillator PWM frequency is adjustable. A resistor to ground sets the current IREF and the internal PWM oscillator frequency. A range of 500Hz
Frequency Adjust to 100kHz can be achieved with practical resistor values. Although oscillator frequency operation below 500Hz is possible, resistors
higher than 10MΩ will be required. The pin then becomes a very high-impedance node and is, therefore, sensitive to noise pickup
and PCB leakage currents. Resistor connection to this pin in slave mode sets the frequency at which current limit reset occurs.
4 Master With no connection, this pin is driven to 5V by an internal 15μA current source. In this mode the device is the master and the SYNC
pin becomes a 0V to 4.2V output, which is High when the power device is on. When the Master/Input is 0V, the SYNC pin is an
input. In slave mode, the output follows the SYNC pin; the output is High when SYNC is High.
5 BOOT The bootstrap capacitor between this pin and the output, supplies the charge to provide the VGS necessary to turn on the power
device. CBOOT should be larger than 100pF. Use of a smaller CBOOT may slow the output rise time, device is specified and tested
with 470pF.
6, 7 OUT1, OUT2 The output is the source of a power DMOS transistor with its drain connected to VPS. Its low on-resistance (0.45Ω typ) assures
low power dissipation in the DRV104. Gate drive to the power device is controlled to provide a slew-rate limited rise-and-fall time.
This reduces the radiated RFI/EMI noise. A flyback diode is needed with inductive loads to conduct the load current during the off
cycle. The external diode should be selected for low forward voltage and low storage time. The internal diode should not be used
as a flyback diode. If devices are connected in parallel, the outputs must be connected through individual diodes. Devices are
current-limit protected for shorts to ground, but not to supply.
8, 9 VPS1, VPS2 These are the load power-supply pins to the drain of the power device. The load supply voltage may exceed the voltage at pin 10
by 5V, but must not exceed 37V.
10 +VS This is the power-supply connection for all but the drain of the power device. The operating range is 8V to 32V.
11 GND This pin must be connected to the system ground for the DRV104 to function. It does not carry the load current when the power
DMOS device is switched on.
12 SYNC The SYNC pin is a 0V to 4.2V copy of the output when the Master/Slave pin is High. As an output, it can supply 100μA with 1kΩ
output resistance. At 2mA, it current limits to either 4.2V or 0V. When the Master pin is Low, it is an input and the threshold is 2V.
SYNC output follows power output in master mode, and is not affected by thermal or current-limit shutdown. Power output follows
SYNC input in slave mode.
13 Status OK Flag Normally High (active Low), a Flag Low signals either an over-temperature or over-current fault. A thermal fault (thermal shutdown)
occurs when the die surface reaches approximately 160°C and latches until the die cools to 140°C. This output requires a pullup
resistor and it can typically sink 2mA, sufficient to drive a low-current LED. Sink current is internally limited at 10mA, typical.
14 Input The input is compatible with standard TTL levels. The device becomes enabled when the input voltage is driven above the typical
switching threshold, 1.8V; below this level, the device is disabled. Input current is typically 1μA when driven High and 1μA when driven
Low. The input should not be directly connected to the power supply (VS) or damage will occur.


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