Datasheet

 
 
SLVS325C − MARCH 2001 − REVISED MAY 2002
      
  
    
 
    
 
FEATURES
D 100-mA Low-Dropout Regulator With EN
D Available in 1.8-V, 3.3-V, 4.7-V, and Adj.
D High PSRR (70 dB at 10 kHz)
D Ultralow Noise (15 µV
RMS
)
D Fast Start-Up Time (63 µs)
D Stable With Any 1-µF Ceramic Capacitor
D Excellent Load/Line Transient
D Very Low Dropout Voltage
(38 mV at Full Load, TPS79147)
D 5-Pin SOT23 (DBV) Package
D TPS792xx Provides EN Options
APPLICATIONS
D Cellular and Cordless Telephones
D VCOs
D RF
D Bluetooth, Wireless LAN
D Handheld Organizers, PDA
DESCRIPTION
The TPS791xx family of low-dropout (LDO)
low-power linear voltage regulators features high
power supply rejection ratio (PSRR), ultralow
noise, fast start-up, and excellent line and load
transient responses in a small outline, SOT23,
package. Each device in the family is stable, with
a small 1-µF ceramic capacitor on the output. The
family uses an advanced, proprietary BiCMOS
fabrication process to yield extremely low dropout
voltages (e.g., 38 mV at 100 mA, TPS79147).
Each device achieves fast start-up times
(approximately 63 µs with a 0.001 µF bypass
capacitor) while consuming very low quiescent
current (170 µA typical). Moreover, when the
device is placed in standby mode, the supply
current is reduced to less than 1 µA. The
TPS79118 exhibits approximately 15 µV
RMS
of
output voltage noise with a 0.1 µF bypass
capacitor. Applications with analog components
that are noise sensitive, such as portable RF
electronics, benefit from the high PSRR and low
noise features as well as the fast response time.
3
2
4
5
DBV PACKAGE
(TOP VIEW)
1IN
GND
EN
OUT
BYPASS
3
2
4
6
DBV PACKAGE
(TOP VIEW)
1IN
EN
OUT
BYPASS
5
FB
Adjustable Option
Fixed Option
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
100 1 k 10 k 100 k
I
O
= 1 mA
V
O
= 4.3 V
C
o
= 1 µF
C
(byp)
= 0.1 µF
I
O
= 100 mA
f − Frequency − Hz
Output Spectral Noise Density −
TPS79133
OUTPUT SPECTRAL NOISE DENSITY
vs
FREQUENCY
V/ Hzµ
60
50
30
20
10 100 1 k 10 k
70
90
100
100 k 1 M 10 M
40
80
Ripple Rejection − dB
f − Frequency − Hz
TPS79133
RIPPLE REJECTION
vs
FREQUENCY
V
I
= 4.3 V
C
o
= 10 µF
C
(byp)
= 0.01 µF
I
O
= 10 mA
I
O
= 100 mA
GND
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