SGLS162A − APRIL 2003 − REVISED JULY 2004
FEATURES
DQualification in Accordance With AEC-Q100†
DQualified for Automotive Applications
DCustomer-Specific Configuration Control Can
Be Supported Along With Major-Change
Approval
DESD Protection Exceeds 2000 V Per
MIL-STD-883, Method 3015; Exceeds 200 V
Using Machine Model (C = 200 pF, R = 0)
D200-mA Low-Dropout Regulator With EN
DAvailable in 1.8-V, 2.5-V, 2.8-V, 2.85-V, 3-V,
3.3-V, 4.75-V, and Adjustable
DHigh PSRR (70 dB at 10 kHz)
DUltralow Noise (32 µV)
DFast Start-Up Time (50 µs)
DStable With a 2.2-µF Ceramic Capacitor
DExcellent Load/Line Transient
DVery Low Dropout Voltage
(112 mV at Full Load, TPS79330)
D5-Pin SOT23 (DBV) Package
†Contact factory for details. Q100 qualification data available on
request.
APPLICATIONS
DVCOs
DRF
DBluetooth, Wireless LAN
DESCRIPTION
The TPS793xx 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 2.2-µF ceramic capacitor on the
output. The TPS793xx family uses an advanced,
proprietary BiCMOS fabrication process to yield
extremely low dropout voltages (e.g., 112 mV at 200
mA, TPS79330). Each device achieves fast start-up
times (approximately 50 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 TPS79328 exhibits approximately 32
µVRMS 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.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments
semiconductor products and disclaimers thereto appears at the end of this data sheet.
!"#$%&'!$" !( )*%%+"' &( $# ,*-.!)&'!$" /&'+0 %$/*)'(
)$"#$% '$ (,+)!#!)&'!$"( ,+% '1+ '+%( $# +2&( "('%*+"'( ('&"/&%/ 3&%%&"'40
%$/*)'!$" ,%$)+((!"5 /$+( "$' "+)+((&%!.4 !").*/+ '+('!"5 $# &.. ,&%&+'+%(0
Copyright 2003 − 2004, Texas Instruments Incorporated
Bluetooth is a trademark owned by Bluetooth SIG, Inc.
3
2
4
5
DBV PACKAGE
(TOP VIEW)
1IN
GND
EN
OUT
BYPASS
Fixed Option
3
2
4
6
DBV PACKAGE
(TOP VIEW)
1IN
GND
EN
OUT
BYPASS
5FB
Adjustable Option
SGLS162A − APRIL 2003 − REVISED JULY 2004
www.ti.com
2
10 100 1 k 10 k
10
40
80
100 k 1 M 10 M
Ripple Rejection − dB
f − Frequency − Hz
TPS79328
RIPPLE REJECTION
vs
FREQUENCY
IO = 10 mA
50
0
VI = 3.8 V
Co = 10 µF
C(byp) = 0.01 µF
IO = 200 mA
20
30
60
70
90
100
0
0.05
0.1
0.15
0.2
0.25
0.3
100 1 k 10 k 100 k
f − Frequency − Hz
IO = 1 mA
VI = 3.8 V
Co = 2.2 µF
C(byp) = 0.1 µF
IO = 200 mA
TPS79328
OUTPUT SPECTRAL NOISE DENSITY
vs
FREQUENCY
V/ HzOutput Spectral Noise Density − µ
AVAILABLE OPTIONS
TJVOLTAGE PACKAGE PART NUMBER SYMBOL
1.2 to 5.5 V TPS79301DBVRQ1†PGV1
1.8 V TPS79318DBVRQ1†PHH1
2.5 V TPS79325DBVRQ1†PGW1
−40°C to 125°C
2.8 V
SOT23
TPS79328DBVRQ1†‡ PGX1
−40
°
C to 125
°
C
2.85 V
SOT23
(DBV) TPS793285DBVRQ1†‡ PHI1
3 V
(DBV)
TPS79330DBVRQ1†‡ PGY1
3.3 V TPS793333DBVRQ1†PHU1
4.75 V TPS793475DBVRQ1†‡ PHJ1
†The DBVR indicates tape and reel of 3000 parts.
‡Product preview
SGLS162A − APRIL 2003 − REVISED JULY 2004
www.ti.com
3
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)†
Input voltage range −0.3 V to 6 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Voltage range at EN −0.3 V to VI + 0.3 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Voltage on OUT −0.3 V to 6 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Peak output current internally limited. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ESD rating, HBM 2 kV. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ESD rating, CDM 500 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Continuous total power dissipation See Dissipation Rating Table. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating virtual junction temperature range, TJ−40°C to 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating ambient temperature range, TA−40°C to 85°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage temperature range, Tstg −65°C to 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
†Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only , and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not implied.
Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
(1) All voltage values are with respect to network ground terminal.
DISSIPATION RATING TABLE
BOARD PACKAGE RθJC RθJA DERATING FACTOR
ABOVE TA = 25°CTA ≤ 25°C
POWER RATING TA = 70°C
POWER RATING TA = 85°C
POWER RATING
Low K‡DBV 63.75 °C/W 256 °C/W 3.906 mW/°C391 mW 215 mW 156 mW
High K§DBV 63.75 °C/W 178.3 °C/W 5.609 mW/°C561 mW 308 mW 224 mW
‡The JEDEC low K (1s) board design used to derive this data was a 3-inch x 3-inch, two layer board with 2 ounce copper traces on top of the board.
§The JEDEC high K (2s2p) board design used to derive this data was a 3-inch x 3-inch, multilayer board with 1 ounce internal power and ground
planes and 2 ounce copper traces on top and bottom of the board.
SGLS162A − APRIL 2003 − REVISED JULY 2004
www.ti.com
4
electrical characteristics over recommended operating free-air temperature range EN = VI,
TJ = −40 to 125 °C, VI = VO(typ) + 1 V, IO = 1 mA, Co = 10 µF, C(byp) = 0.01 µF (unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
VIInput voltage (see Note 2) 2.7 5.5 V
IOContinuous output current (see Note 3) 0 200 mA
TJOperating junction temperature −40 125 °C
TPS79301 0 µA< IO < 200 mA,
(see Note 4 ) 1.22 V ≤ VO ≤ 5.2 V, 0.98 VO1.02 VOV
TPS79318
TJ = 25°C 1.8
V
TPS79318
0 µA< IO < 200 mA, 2.8 V < VI < 5.5 V 1.764 1.836
V
TPS79325
TJ = 25°C 2.5
V
TPS79325
0 µA< IO < 200 mA, 3.5 V < VI < 5.5 V 2.45 2.55
V
TPS79328
TJ = 25°C 2.8
V
Output voltage
TPS79328
0 µA< IO < 200 mA, 3.8 V < VI < 5.5 V 2.744 2.856
V
Output voltage
TPS793285
TJ = 25°C 2.85
V
TPS793285
0 µA< IO < 200 mA, 3.85 V < VI < 5.5 V 2.793 2.907
V
TPS79330
TJ = 25°C 3
V
TPS79330
0 µA< IO < 200 mA, 4 V < VI < 5.5 V 2.94 3.06
V
TPS79333
TJ = 25°C 3.3
V
TPS79333
0 µA≤ IO < 200 mA, 4.3 V < VI < 5.5 V 3.234 3.366
V
TPS793475
TJ = 25°C 4.75
V
TPS793475
0 µA< IO < 200 mA, 5.25 V < VI < 5.5 V 4.655 4.845
V
Quiescent current (GND current)
0 µA< IO < 200 mA, TJ = 25°C 170 µA
Quiescent current (GND current)
0 µA< IO < 200 mA 220 µA
Load regulation 0 µA< IO < 200 mA, TJ = 25°C 5 mV
Output voltage line regulation (
∆
VO/VO)
(see
VO + 1 V < VI ≤ 5.5 V, TJ = 25°C 0.05
%/V
Output voltage line regulation (∆VO/VO)
(see
Note 5) VO + 1 V < VI ≤ 5.5 V 0.12
%/V
C(byp) = 0.001 µF 55
Output noise voltage (TPS79328)
BW = 200 Hz to 100 kHz,
C(byp) = 0.0047 µF 36
µVRMS
Output noise voltage (TPS79328)
BW = 200 Hz to 100 kHz,
IO = 200 mA, TJ = 25°CC(byp) = 0.01 µF 33 µ
V
RMS
IO = 200 mA, TJ = 25 C
C(byp) = 0.1 µF 32
RL = 14 Ω,
C(byp) = 0.001 µF 50
Time, start-up (TPS79328)
R
L
= 14
Ω
,
Co = 1 µF, TJ = 25
°
C
C(byp) = 0.0047 µF 70 µs
Time, start-up (TPS79328)
Co = 1
µ
F, TJ = 25°C
C(byp) = 0.01 µF 100
µs
Output current limit VO = 0 V, See Note 4 285 600 mA
Standby current EN = 0 V, 2.7 V < VI < 5.5 V 0.07 1 µA
High level enable input voltage 2.7 V < VI < 5.5 V 2 V
Low level enable input voltage 2.7 V < VI < 5.5 V 0.7 V
Input current (EN) EN = 0 −1 1 µA
Input current (FB) (TPS79301) FB = 1.8 V 1µA
(1))To calculate the minimum input voltage for your maximum output current, use the following formula:
VI(min) = VO(max) + VDO (max load)
(2))Continuous output current and operating junction temperature are limited by internal protection circuitry, but it is not recommended that the device
operate under conditions beyond those specified in this table for extended periods of time.
(3))The minimum IN operating voltage is 2.7 V or VO(typ) + 1 V, whichever is greater . The maximum IN voltage is 5.5 V. The maximum output current
is 200 mA.
(4))If VO≤ 2.5 V then VImin = 2.7 V, VImax = 5.5 V :
Line Reg. (mV) +ǒ%ńVǓ VOǒVImax *2.7 VǓ
100 1000
If VO ≥ 2.5 V then VImin = VO + 1 V, VImax = 5.5 V.
SGLS162A − APRIL 2003 − REVISED JULY 2004
www.ti.com
5
electrical characteristics over recommended operating free-air temperature range EN = VI,
TJ = −40 to 125 °C, VI = VO(typ) + 1 V, IO = 1 mA, Co = 10 µF, C(byp) = 0.01 µF (unless otherwise noted)
(continued)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
f = 100 Hz, TJ = 25°C, IO = 10 mA 70
Power supply ripple rejection
TPS79328
f = 100 Hz, TJ = 25°C, IO = 200 mA 68
dB
Power supply ripple rejection
TPS79328
f = 10 kHz, TJ = 25°C, IO = 200 mA 70
dB
f = 100 kHz, TJ = 25°C, IO = 200 mA 43
TPS79328
IO = 200 mA, TJ = 25°C 120
TPS79328
IO = 200 mA 200
TPS793285
IO = 200 mA, TJ = 25°C 120
mV
TPS793285
IO = 200 mA 200
mV
Dropout voltage (see Note 6)
TPS79330
IO = 200 mA, TJ = 25°C112
Dropout voltage (see Note 6)
TPS79330
IO = 200 mA 200
TPS79333
IO = 200 mA, TJ = 25°C 102
mV
TPS79333
IO = 200 mA 180
mV
TPS793475
IO = 200 mA, TJ = 25°C 77
mV
TPS793475
IO = 200 mA 125
mV
UVLO threshold VCC rising 2.25 2.65 V
UVLO hysteresis TJ = 25°C VCC rising 100 mV
(1) IN voltage equals VO(typ) − 100 mV; The TPS79325 dropout voltage is limited by the input voltage range limitations.
SGLS162A − APRIL 2003 − REVISED JULY 2004
www.ti.com
6
FUNCTIONAL BLOCK DIAGRAM—ADJUSTABLE VERSION
_+
Thermal
Shutdown
Bandgap
Reference
VIN
Current
Sense
R2
VIN
GND
EN
VOUT
SHUTDOWN
Vref
UVLO
ILIM
External to
the Device
R1
UVLO
250 kΩBypass
FB
FUNCTIONAL BLOCK DIAGRAM—FIXED VERSION
_+
Thermal
Shutdown
VIN
Current
Sense
R1
R2
VIN
GND
EN
VOUT
SHUTDOWN
Vref
UVLO
ILIM
Bandgap
Reference
UVLO
250 kΩBypass
Terminal Functions
TERMINAL
I/O
DESCRIPTION
NAME ADJ FIXED
I/O
DESCRIPTION
BYPASS 4 4 An external bypass capacitor, connected to this terminal, in conjunction with an internal resistor , creates a
low-pass filter to further reduce regulator noise.
EN 3 3 I The EN terminal is an input which enables or shuts down the device. When EN goes to a logic high, the device
will b e enabled. When the device goes to a logic low, the device is in shutdown mode.
FB 5 N/A I This terminal is the feedback input voltage for the adjustable device.
GND 2 2 Regulator ground
IN 1 1 I The IN terminal is the input to the device.
OUT 6 5 O The OUT terminal is the regulated output of the device.
SGLS162A − APRIL 2003 − REVISED JULY 2004
www.ti.com
7
TYPICAL CHARACTERISTICS
Figure 1
2.795
2.796
2.797
2.798
2.799
2.8
2.801
2.802
2.803
2.804
2.805
0 50 100 150 200
IO − Output Current − mA
TPS79328
OUTPUT V O LTAGE
vs
OUTPUT CURRENT
VI = 3.8 V
Co = 10 µF
TJ = 25°C
− Output Voltage − V
VO
Figure 2
2.775
2.78
2.785
2.79
2.795
2.8
2.805
−40−25−10 5 20 35 50 65 80 95 110 125
TJ − Junction Temperature − °C
TPS79328
OUTPUT V O LTAGE
vs
JUNCT I O N T E M P E R ATURE
− Output Voltage − V
VO
IO = 200 mA
IO = 1 mA
VI = 3.8 V
Co = 10 µF
Figure 3
0
50
100
150
200
250
−40−25−10 5 20 35 50 65 80 95 110 125
TJ − Junction Temperature − °C
TPS79328
GROUND CURRENT
vs
JUNCT I O N T E M P E R ATURE
Ground Current − Aµ
IO = 1 mA
VI = 3.8 V
Co = 10 µF
IO = 200 mA
Figure 4
0
0.05
0.1
0.15
0.2
0.25
0.3
100 1 k 10 k 100 k
f − Frequency − Hz
IO = 1 mA
VI = 3.8 V
Co = 2.2 µF
C(byp) = 0.1 µF
IO = 200 mA
TPS79328
OUTPUT SPECTRAL NOISE DENSITY
vs
FREQUENCY
V/ HzOutput Spectral Noise Density − µ
Figure 5
0
0.05
0.1
0.15
0.2
0.25
0.3
100 1 k 10 k 100
k
V/ HzOutput Spectral Noise Density − µ
f − Frequency − Hz
IO = 1 mA
IO = 200 mA
TPS79328
OUTPUT SPECTRAL NOISE DENSITY
vs
FREQUENCY
VI = 3.8 V
Co = 10 µF
C(byp) = 0.1 µF
Figure 6
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
100 1 k 10 k 100
k
f − Frequency − Hz
V/ HzOutput Spectral Noise Density −
TPS79328
OUTPUT SPECTRAL NOISE DENSIT
Y
vs
FREQUENCY
VI = 3.8 V
IO = 200 mA
Co= 10 µF
C(byp) = 0.1 µF
C(byp) = 0.001 µF
µ
C(byp) = 0.0047 µF
C(byp) = 0.01 µF
Figure 7
0.001 0.01 0.1
RMS − Root Mean Squared Output Noise −
ROOT MEAN SQUARED OUTPUT NOISE
vs
BYPASS CAPACITANCE
(RMS)
Vµ
C(byp) − Bypass Capacitance − µF
0
10
20
30
40
50
60 VO = 2.8 V
IO = 200 mA
Co = 10 µF
BW = 100 Hz to 100
kHz
Figure 8
100 1 M10 1 k
f − Frequency − Hz
10 k
− Output Impedance −ZoΩ
OUTPUT IMPEDANCE
vs
FREQUENCY
100 k
IO = 1 mA
0
0.5
1
1.5
2
2.5
0
IO = 100 mA
10 M
VI = 3.8 V
Co = 10 µF
TJ = 25°C
0
20
40
60
80
100
120
140
160
180
−40−25−10 5 20 35 50 65 80 95 110 125
IO = 200 mA
IO = 10 mA
VI = 2.7 V
Co = 10 µF
TJ − Junction Temperature − °C
− Dropout Voltage − mV
VDO
TPS79328
DROPOUT VO LTAGE
vs
JUNCT I O N T E M P E R ATURE
Figure 9
SGLS162A − APRIL 2003 − REVISED JULY 2004
www.ti.com
8
TYPICAL CHARACTERISTICS
Figure 10
10 100 1 k 10 k
10
40
80
100 k 1 M 10 M
Ripple Rejection − dB
f − Frequency − Hz
TPS79328
RIPPLE REJECTION
vs
FREQUENCY
IO = 10 mA
50
0
VI = 3.8 V
Co = 10 µF
C(byp) = 0.01 µF
IO = 200 mA
20
30
60
70
90
100
Figure 11
10 100 1 k 10 k
20
60
100
100 k 1 M 10 M
Ripple Rejection − dB
f − Frequency − Hz
TPS79328
RIPPLE REJECTION
vs
FREQUENCY
VI = 3.8 V
Co = 2.2 µF
C(byp) = 0.01 µF
IO = 10 mA
IO = 200 mA
40
70
90
30
50
80
10
0
Figure 12
10 100 1 k 10 k
20
60
100
100 k 1 M 10 M
Ripple Rejection − dB
f − Frequency − Hz
TPS79328
RIPPLE REJECTION
vs
FREQUENCY
VI = 3.8 V
Co = 2.2 µF
C(byp) = 0.1 µF
IO = 10 mA
IO = 200 mA
40
70
90
30
50
80
10
0
Figure 13
3
TPS79328
OUTPUT VOLTAGE, ENABLE VOL TAG
E
vs
TIME (START-UP)
VO
t − Time − µs
0604020 80 100 140120 160 180 200
− Output Voltage − V
VI = 3.8 V
VO = 2.8 V
IO = 200 mA
Co = 2.2 µF
TJ = 25°C
Enable Voltage − V
1
2
0
0
2C(byp) = 0.0047 µF
C(byp) = 0.01 µF
4
C(byp) = 0.001 µF
Figure 14
TPS79328
LINE TRANSIENT RESPONSE
VO
t − Time − µs
0302010 40 50 7060 80 90 100
− Output Voltage − mV
IO = 200 mA
Co = 2.2 µF
C(byp) = 0.01 µF
VI− Input Voltage −
0
-20
3.8
dv
dt +0.4 V
µs
mV
20
4.8
Figure 15
t − Time − µs
TPS79328
LOAD TRANSIENT RESPONSE
0
0 15010050 200 250 350300 400 450
20
0
−20
VO
Output Voltage − mV
∆ − Change In
100
50
0
− Output Current − mA
IO
VI = 3.8 V
Co = 10 µF
−40
200
300 di
dt +0.02A
µs
1mA
Figure 16
500 mV/div
1s/div
POWER UP / POWER DOWN
VIVO
VO = 3 V
RL = 15 Ω
Figure 17
100
50
0 20 40 60 80 100 120
DC Dropuoy Voltage − mV
150
200
DC DROPOUT VOLTAGE
vs
OUTPUT CURRENT
250
140 160 180 200
0
IO − Output Current − mA
TJ = 125°C
TJ = 25°C
TJ = −55°C
Figure 18
0
50
100
150
200
2.5 3 3.5 4 4.5 5
TPS79301
DROPOUT VO LTAGE
vs
INPUT VOLT AGE
VI − Input Voltage − V
− Dropout Voltage − mV
VDO
IO = 200 mA
TJ = 25°C
TJ = −40°C
TJ = 125°C
SGLS162A − APRIL 2003 − REVISED JULY 2004
www.ti.com
9
TYPICAL CHARACTERISTICS
Figure 19
2
3
4
1.5 2.5 3.523
TJ = 25°C
IO = 200 mA
− Minimum Required Input Voltage − V
MINIMUM REQUIRED INPUT VOLT AGE
vs
OUTPUT VOLT AGE
VO − Output Voltage − V
VI
1.75 2.25 2.75 3.25
2.8
TJ = 125°C
TJ = −40°C
Figure 20
0.01
0.1
10
100
0 0.02 0.04 0.06 0.08 0.2
IO − Output Current − A
ESR − Equivalent Series Resistance − Ω
TYPICAL REGIONS OF STABILITY
EQUIVALENT SERIES RESISTANCE (ESR
)
vs
OUTPUT CURRENT
1
Region of Instability
Region of Stability
Co = 2.2 µF
VI = 5.5 V, VO ≥ 1.5 V
TJ = −40°C to 125°C
Figure 21
TYPICAL REGIONS OF STABILITY
EQUIVALENT SERIES RESISTANCE (ESR
)
vs
OUTPUT CURRENT
0.01
0.1
10
100
0 0.02 0.04 0.06 0.08 0.2
IO − Output Current − A
ESR − Equivalent Series Resistance − Ω
1
Region of Instability
Region of Stability
Co = 10 µF
VI = 5.5 V
TJ = −40°C to 125°C
SGLS162A − APRIL 2003 − REVISED JULY 2004
www.ti.com
10
APPLICATION INFORMATION
The TPS793xx family of low-dropout (LDO) regulators has
been optimized for use in noise-sensitive battery-operated
equipment. The device features extremely low dropout
voltages, high PSRR, ultralow output noise, low quiescent
current (170 µA typically), and enable-input to reduce
supply currents to less than 1 µA when the regulator is
turned off.
A typical application circuit is shown in Figure 22.
0.1 µF
BYPASS
OUT
1
3
IN
EN
GND
2
4
5
VI
VO
2.2 µF
+
TPS793xx
0.01 µF
Figure 22. Typical Application Circuit
EXTERNAL CAPACITOR REQUIREMENTS
A 0.1-µF or larger ceramic input bypass capacitor,
connected between IN and GND and located close to the
TPS793xx, is required for stability and will improve
transient response, noise rejection, and ripple rejection. A
higher-value electrolytic input capacitor may be necessary
if large, fast-rise-time load transients are anticipated and
the device is located several inches from the power
source.
Like all low dropout regulators, the TPS793xx requires an
output capacitor connected between OUT and GND to
stabilize the internal control loop. The minimum
recommended cap a c i t a n c e i s 2 . 2 µF. Any 2.2 µF or larger
ceramic capacitor is suitable, provided the capacitance
does not vary significantly over temperature.
The internal voltage reference is a key source of noise in
an LDO regulator. The TPS793xx has a BYPASS pin
which is connected to the voltage reference through a
250-kΩ internal resistor. The 250-kΩ internal resistor, in
conjunction with an external bypass capacitor connected
to the BYPASS pin, creates a low pass filter to reduce the
voltage reference noise and, therefore, the noise at the
regulator output. In order for the regulator to operate
properly, the current flow out of the BYPASS pin must be
at a minimum, because any leakage current will create an
IR drop across the internal resistor thus creating an output
error. Therefore, the bypass capacitor must have minimal
leakage current.
For example, the TPS79328 exhibits only 32 µVRMS of
output voltage noise using a 0.1-µF ceramic bypass
capacitor and a 2.2-µF ceramic output capacitor. Note that
the output starts up slower as the bypass capacitance
increases due to the RC time constant at the BYPASS pin
that is created by the internal 250-kΩ resistor and external
capacitor.
SGLS162A − APRIL 2003 − REVISED JULY 2004
www.ti.com
11
APPLICATION INFORMATION
BOARD LAYOUT RECOMMENDATION TO
IMPROVE PSRR AND NOISE
PERFORMANCE
To improve ac measurements like PSRR, output noise,
and transient response, it is recommended that the board
be designed with separate ground planes for VIN and
VOUT, with each ground plane connected only at the GND
pin of the device. In addition, the ground connection for the
bypass capacitor should connect directly to the GND pin
of the device.
POWER DISSIPATION AND JUNCTION
TEMPERATURE
Specified regulator operation is assured to a junction
temperature of 1 2 5 °C; the maximum junction temperature
should be restricted to 125°C under normal operating
conditions. This restriction limits the power dissipation the
regulator can handle in any given application. To ensure
the junction temperature is within acceptable limits,
calculate the maximum allowable dissipation, PD(max),
and the actual dissipation, PD, which must be less than or
equal to PD(max).
The maximum-power-dissipation limit is determined using
the following equation:
PD(max) +TJmax *TA
RθJA
Where:
TJmax is the maximum allowable junction temperature.
RθJA is the thermal resistance junction-to-ambient for the package, see the dissipation rating table.
TA is the ambient temperature.
(1)
The regulator dissipation is calculated using:
PD+ǒVI*VOǓ IO(2)
Power dissipation resulting from quiescent current is
negligible. Excessive power dissipation triggers the
thermal protection circuit.
PROGRAMMING THE TPS79301
ADJUSTABLE LDO REGULATOR
The output voltage of the TPS79301 adjustable regulator
is programmed using an external resistor divider as shown
in Figure 23. The output voltage is calculated using:
VO+Vref ǒ1)R1
R2Ǔ(3)
Where:
Vref = 1.2246 V typ (the internal reference voltage)
SGLS162A − APRIL 2003 − REVISED JULY 2004
www.ti.com
12
APPLICATION INFORMATION
PROGRAMMING THE TPS79301
ADJUSTABLE LDO REGULATOR
(CONTINUED)
Resistors R1 and R2 should be chosen for approximately
50-µA divider current. Lower value resistors can be used
for improved noise performance, but the solution
consumes more power. Higher resistor values should be
avoided as leakage current into/out of FB across R1/R2
creates an offset voltage that artificially
increases/decreases the feedback voltage and thus
erroneously decreases/increases VO. The recommended
design procedure is to choose R2 = 30.1 kΩ to set the
divider current at 50 µA, C1 = 15 pF for stability, and then
calculate R1 using:
R1 +ǒVO
Vref *1Ǔ R2 (4)
In order to improve the stability of the adjustable version,
it is suggested that a small compensation capacitor be
placed between OUT and FB. For voltages <1.8 V, the
value o f this capacitor should be 100 pF. For voltages >1.8
V, the approximate value of this capacitor can be
calculated as:
C1 +(3 x 10–7)x(R1)R2)
(R1 x R2) (5)
The suggested value of this capacitor for several resistor
ratios is shown in the table below. If this capacitor is not
used (such as i n a unity-gain configuration) or if an output
voltage <1.8 V is chosen, then the minimum
recommended output capacitor is 4.7 µF instead of 2.2 µF.
22 pF
15 pF
15 pF
OUTPUT VOLT AGE
PROGRAMMING GUIDE
OUTPUT
VOLTAGE R1 R2
2.5 V
3.3 V
3.6 V
C1
31.6 kΩ
51 kΩ
59 kΩ
30.1 kΩ
30.1 kΩ
30.1 kΩ
VO
VI
OUT
FB
R1
R2
GND
EN
IN
≤0.7 V
≥2 V
TPS79301
1 µF
BYPASS
0.01 µF
1 µF
C1
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 i s 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 m 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 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.
PACKAGING INFORMATION
Orderable Device Status (1) Package
Type Package
Drawing Pins Package
Qty Eco Plan (2) Lead/Ball Finish MSL Peak Temp (3)
TPS79301DBVRQ1 ACTIVE SOT-23 DBV 6 3000 None Call TI Level-1-220C-UNLIM
TPS79318DBVRQ1 ACTIVE SOT-23 DBV 5 3000 None Call TI Level-1-220C-UNLIM
TPS79325DBVRQ1 ACTIVE SOT-23 DBV 5 3000 None Call TI Level-1-220C-UNLIM
TPS79333DBVRQ1 ACTIVE SOT-23 DBV 5 3000 None Call TI Level-1-220C-UNLIM
TPS793475DBVRQ1 ACTIVE SOT-23 DBV 5 3000 None Call TI Level-1-220C-UNLIM
(1) The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in
a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2) Eco Plan - May not be currently available - please check http://www.ti.com/productcontent for the latest availability information and additional
product content details.
None: Not yet available Lead (Pb-Free).
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements
for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered
at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Green (RoHS & no Sb/Br): TI defines "Green" to mean "Pb-Free" and in addition, uses package materials that do not contain halogens,
including bromine (Br) or antimony (Sb) above 0.1% of total product weight.
(3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDECindustry standard classifications, and peak solder
temperature.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is
provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the
accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take
reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on
incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited
information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI
to Customer on an annual basis.
PACKAGE OPTION ADDENDUM
www.ti.com 25-Feb-2005
Addendum-Page 1
IMPORTANT NOTICE
Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications,
enhancements, improvements, and other changes to its products and services at any time and to discontinue
any product or service without notice. Customers should obtain the latest relevant information before placing
orders and should verify that such information is current and complete. All products are sold subject to TI’ s terms
and conditions of sale supplied at the time of order acknowledgment.
TI warrants performance of its hardware products to the specifications applicable at the time of sale in
accordance with TI’s standard warranty. Testing and other quality control techniques are used to the extent TI
deems necessary to support this warranty. Except where mandated by government requirements, testing of all
parameters of each product is not necessarily performed.
TI assumes no liability for applications assistance or customer product design. Customers are responsible for
their products and applications using TI components. To minimize the risks associated with customer products
and applications, customers should provide adequate design and operating safeguards.
TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right,
copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process
in which TI products or services are used. Information published by TI regarding third-party products or services
does not constitute a license from TI to use such products or services or a warranty or endorsement thereof.
Use of such information may require a license from a third party under the patents or other intellectual property
of the third party, or a license from TI under the patents or other intellectual property of TI.
Reproduction of information in TI data books or data sheets is permissible only if reproduction is without
alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Reproduction
of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for
such altered documentation.
Resale of T I products or services with statements different from or beyond the parameters stated by TI for that
product or service voids all express and any implied warranties for the associated TI product or service and
is an unfair and deceptive business practice. TI is not responsible or liable for any such statements.
Following are URLs where you can obtain information on other Texas Instruments products and application
solutions:
Products Applications
Amplifiers amplifier.ti.com Audio www.ti.com/audio
Data Converters dataconverter.ti.com Automotive www.ti.com/automotive
DSP dsp.ti.com Broadband www.ti.com/broadband
Interface interface.ti.com Digital Control www.ti.com/digitalcontrol
Logic logic.ti.com Military www.ti.com/military
Power Mgmt power.ti.com Optical Networking www.ti.com/opticalnetwork
Microcontrollers microcontroller.ti.com Security www.ti.com/security
Telephony www.ti.com/telephony
Video & Imaging www.ti.com/video
Wireless www.ti.com/wireless
Mailing Address: Texas Instruments
Post Office Box 655303 Dallas, Texas 75265
Copyright 2005, Texas Instruments Incorporated
