ZHCSLK0A July 2021 – December 2021 TPS22992
PRODUCTION DATA
A capacitor to GND on the CT pin sets the slew rate, and the higher the capacitance the lower the slew rate. The voltage on the CT pin can be as high as 15 V; therefore, the minimum voltage rating for the CT capacitor must be 30 V for optimal performance. Rise times for VBIAS = 5 V are shown below.
|
CT Capacitor |
VIN = 5 V |
VIN = 3.3 V |
VIN = 1.8 V |
VIN = 1.2 V |
VIN = 0.8 V |
|---|---|---|---|---|---|
|
0 pF |
147 µs |
113 µs |
77 µs |
59 µs |
45 µs |
|
220 pF |
426 µs |
297 µs |
179 µs |
129 µs |
94 µs |
|
1000 pF |
1430 µs |
962 µs |
553 µs |
386 µs |
282 µs |
|
4700 pF |
6130 µs |
4090 µs |
2330 µs |
1640 µs |
1180 µs |
The following equation can be used to estimate the rise time for different VIN and CT capacitors at VBIAS = 5 V.
Where:
tR = Rise time in µs
VIN = Input voltage in V
CT = CT capacitance in pF