ZHCSJ20C August 2018 – March 2019 UCC21530-Q1
The UCC21530-Q1 has an internal under voltage lock out (UVLO) protection feature on the supply circuit blocks between the VDD and VSS pins for both outputs. When the VDD bias voltage is lower than VVDD_ON at device start-up or lower than VVDD_OFF after start-up, the VDD UVLO feature holds the effected output low, regardless of the status of the input pins (INA and INB).
When the output stages of the driver are in an unbiased or UVLO condition, the driver outputs are held low by an active clamp circuit that limits the voltage rise on the driver outputs (Illustrated in Figure 34). In this condition, the upper PMOS is resistively held off by RHi-Z while the lower NMOS gate is tied to the driver output through RCLAMP. In this configuration, the output is effectively clamped to the threshold voltage of the lower NMOS device, typically less than 1.5V, when no bias power is available.
The VDD UVLO protection has a hysteresis feature (VVDD_HYS). This hysteresis prevents chatter when there is ground noise from the power supply. Also this allows the device to accept small drops in bias voltage, which is bound to happen when the device starts switching and operating current consumption increases suddenly.
The input side of the UCC21530-Q1 also has an internal under voltage lock out (UVLO) protection feature. The device isn't active unless the voltage, VCCI, is going to exceed VVCCI_ON on start up. The signal will cease to be delivered once the pin receives a voltage less than VVCCI_OFF. In the same way as the VDD UVLO, there is hysteresis (VVCCI_HYS) to ensure stable operation.
UCC21530-Q1 can withstand an absolute maximum of 30 V for VDD, and 20 V for VCCI.
|VCCI-GND < VVCCI_ON during device start up||H||L||L||L|
|VCCI-GND < VVCCI_ON during device start up||L||H||L||L|
|VCCI-GND < VVCCI_ON during device start up||H||H||L||L|
|VCCI-GND < VVCCI_ON during device start up||L||L||L||L|
|VCCI-GND < VVCCI_OFF after device start up||H||L||L||L|
|VCCI-GND < VVCCI_OFF after device start up||L||H||L||L|
|VCCI-GND < VVCCI_OFF after device start up||H||H||L||L|
|VCCI-GND < VVCCI_OFF after device start up||L||L||L||L|
|CONDITION||INPUT: INx||OUTPUT: OUTx|
|VDDx-VSSx < VVDD_ON during device start up||L||L|
|VDDx-VSSx < VVDD_ON during device start up||H||L|
|VDDx-VSSx < VVDD_OFF after device start up||L||L|
|VDDx-VSSx < VVDD_OFF after device start up||H||L|