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