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TPS79301, TPS79318
TPS79325, TPS79328, TPS793285
TPS79330, TPS79333, TPS793475
SLVS348H – JULY 2001 – REVISED OCTOBER 2004
APPLICATION INFORMATION (continued)
OUTPUT VOLTAGE
PROGRAMMING GUIDE
V
IN
1
µF
IN
EN
NR
0.01
µF
GND
FB
R2
OUT
TPS793xx
V
OUT
R1
C1
1
µ
F
OUTPUT
VOLTAGE
1.22 V
2.5 V
3.3 V
3.6 V
R1
short
R2
open
C1
0 pF
22 pF
15 pF
15 pF
31.6 k
Ω
30.1 k
Ω
51 k
Ω
30.1 k
Ω
59 k
Ω
30.1 k
Ω
Figure 23. TPS79301 Adjustable LDO Regulator Programming
Regulator Protection
The TPS793xx PMOS-pass transistor has a built-in back diode that conducts reverse current when the input
voltage drops below the output voltage (e.g., during power-down). Current is conducted from the output to the
input and is not internally limited. If extended reverse voltage operation is anticipated, external limiting might be
appropriate.
The TPS793xx features internal current limiting and thermal protection. During normal operation, the TPS793xx
limits output current to approximately 400 mA. When current limiting engages, the output voltage scales back
linearly until the overcurrent condition ends. While current limiting is designed to prevent gross device failure,
care should be taken not to exceed the power dissipation ratings of the package or the absolute maximum
voltage ratings of the device. If the temperature of the device exceeds approximately 165°C, thermal-protection
circuitry shuts it down. Once the device has cooled down to below approximately 140°C, regulator operation
resumes.
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