Figure 4-2 shows the TPS7B4255-Q1 pin diagram for the DYB package. For a detailed description of
the device pins, see the Pin Configuration and Functions section in the TPS7B4255-Q1 data sheet.
Figure 4-2 Pin Diagram (DYB Package)
Table 4-6 Pin FMA for Device Pins
Short-Circuited to Ground
Pin Name
Pin No.
Description of Potential Failure Effects
Failure Effect Class
ADJ/EN
1
The device is disabled, resulting in no
output voltage.
B
GND
2
No effect. Normal operation.
D
IN
3
Power is not supplied to the device.
System performance depends on upstream current limiting.
B
OUT
4
Regulation is not possible, the device
operates at current limit. The device can cycle in and out of
thermal shutdown.
B
GND
5
No effect. Normal operation.
D
Table 4-7 Pin FMA for Device Pins
Open-Circuited
Pin Name
Pin No.
Description of Potential Failure Effects
Failure Effect Class
ADJ/EN
1
The device state is unknown. If the
device is on, the output voltage is indeterminate.
B
GND
2
The device operates normally with
slightly degraded performance as long as pin 5 is connected
properly.
C
IN
3
Power is not supplied to the device.
B
OUT
4
The device output is disconnected from
the load.
B
GND
5
The device operates normally with
slightly degraded performance as long as pin 2 is connected
properly.
C
Table 4-8 Pin FMA for Device Pins
Short-Circuited to Adjacent Pin
Pin Name
Pin No.
Shorted to
Description of Potential Failure Effects
Failure Effect Class
ADJ/EN
1
GND
The device is disabled, resulting in no
output voltage.
B
GND
2
IN
Power is not supplied to the device.
System performance depends on upstream current limiting.
B
OUT
4
GND
Regulation is not possible, the device
operates at current limit. The device can cycle in and out of
thermal shutdown.
B
Table 4-9 Pin FMA for Device Pins
Short-Circuited to
Supply
Pin Name
Pin No.
Description of Potential Failure Effects
Failure Effect Class
ADJ/EN
1
The device operates as a switch in
dropout mode. The output tracks the input minus the dropout voltage.
B
GND
2
Power is not supplied to the device.
System performance depends on upstream current limiting.
B
IN
3
No effect. Normal operation.
D
OUT
4
Regulation is not possible.
VOUT = VIN.
B
GND
5
Power is not supplied to the device.
System performance depends on upstream current limiting.