參數(shù)資料
型號: TPS7148Y
廠商: Texas Instruments, Inc.
元件分類: 基準電壓源/電流源
英文描述: LOW-DROPOUT VOLTAGE REGULATORS
中文描述: 低壓差電壓調節(jié)器
文件頁數(shù): 29/33頁
文件大?。?/td> 541K
代理商: TPS7148Y
TPS7101Q, TPS7133Q, TPS7148Q, TPS7150Q
TPS7101Y, TPS7133Y, TPS7148Y, TPS7150Y
LOW-DROPOUT VOLTAGE REGULATORS
SLVS092F – NOVEMBER 1994 – REVISED JANUARY 1997
29
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
APPLICATION INFORMATION
programming the TPS7101 adjustable LDO regulator (continued)
Resistors R1 and R2 should be chosen for approximately 7-
μ
A divider current. A recommended value for R2
is 169 k
with R1 adjusted for the desired output voltage. Smaller resistors can be used, but offer no inherent
advantage and consume more power. Larger values of R1 and R2 should be avoided as leakage currents at
FB will introduce an error. Solving equation 1 for R1 yields a more useful equation for choosing the appropriate
resistance:
R1
VO
Vref
1
R2
OUTPUT
VOLTAGE
2.5 V
3.3 V
3.6 V
4 V
5 V
6.4 V
R1
R2
UNIT
191
309
348
402
549
750
169
169
169
169
169
169
k
k
k
k
k
k
OUTPUT VOLTAGE
PROGRAMMING GUIDE
VO
VI
PG
OUT
FB
R1
R2
GND
EN
IN
<0.5V
>2.7 V
TPS7101
Power-Good
Indicator
250 k
0.1
μ
F
+
Figure 44. TPS7101 Adjustable LDO Regulator Programming
power-good indicator
The TPS71xx features a power-good (PG) output that can be used to monitor the status of the regulator. The
internal comparator monitors the output voltage: when the output drops to between 92% and 98% of its nominal
regulated value, the PG output transistor turns on, taking the signal low. The open-drain output requires a pullup
resistor. If not used, it can be left floating. PG can be used to drive power-on reset circuitry or as a low-battery
indicator. PG does not assert itself when the regulated output voltage falls outside the specified 2% tolerance,
but instead reports an output voltage low, relative to its nominal regulated value.
regulator protection
The TPS71xx PMOS-pass transistor has a built-in back diode that safely conducts reverse currents 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. When extended reverse voltage is anticipated, external limiting may be
appropriate.
The TPS71xx also features internal current limiting and thermal protection. During normal operation, the
TPS71xx limits output current to approximately 1 A. 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. If the temperature of
the device exceeds 165
°
C, thermal-protection circuitry shuts it down. Once the device has cooled, regulator
operation resumes.
相關PDF資料
PDF描述
TPS7150Q LOW-DROPOUT VOLTAGE REGULATORS
TPS7150QPW LOW-DROPOUT VOLTAGE REGULATORS
TPS7150QPWR LOW-DROPOUT VOLTAGE REGULATORS
TPS7150Y LOW-DROPOUT VOLTAGE REGULATORS
TPS7148YD LOW-DROPOUT VOLTAGE REGULATORS
相關代理商/技術參數(shù)
參數(shù)描述
TPS7148YD 制造商:TI 制造商全稱:Texas Instruments 功能描述:LOW-DROPOUT VOLTAGE REGULATORS
TPS7148YP 制造商:TI 制造商全稱:Texas Instruments 功能描述:LOW-DROPOUT VOLTAGE REGULATORS
TPS7148YPW 制造商:TI 制造商全稱:Texas Instruments 功能描述:LOW-DROPOUT VOLTAGE REGULATORS
TPS715 制造商:TI 制造商全稱:Texas Instruments 功能描述:50 mA, 24 V, 3.2 uA Supply Current Low-Dropout Linear Regulator
TPS7150 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Low-Dropo