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LP38852-ADJ
SNVS482F – JANUARY 2007 – REVISED DECEMBER 2015
LP38852-ADJ 1.5-A Fast-Response High-Accuracy Adjustable LDO Linear Regulator With
Enable and Soft-Start
1 Features
3 Description
•
•
•
•
The LP38852-ADJ is a high-current, fast-response
regulator which can maintain output voltage
regulation with extremely low input-to-output voltage
drop. Fabricated on a CMOS process, the device
operates from two input voltages: VBIAS provides
voltage to drive the gate of the N-MOS power
transistor, while VIN is the input voltage which
supplies power to the load. The use of an external
bias rail allows the part to operate from ultralow VIN
voltages. Unlike bipolar regulators, the CMOS
architecture consumes extremely low quiescent
current at any output load current. The use of an NMOS power transistor results in wide bandwidth, yet
minimum external capacitance is required to maintain
loop stability.
1
•
•
•
•
•
Input VIN Range 0.93 V to 5.5 V
Adjustable VOUT Range 0.8 V to 1.8 V
Wide VBIAS Supply Operating Range 3 V to 5.5 V
Dropout Voltage of 130 mV (Typical) at 1.5-A
Load Current
Precision Output Voltage Across All Line and
Load Conditions:
– ±1.5% VADJ for TJ = 25°C
– ±2% VADJ for 0°C ≤ TJ ≤ +125°C
– ±3% VADJ for –40°C ≤ TJ ≤ +125°C
Overtemperature and Overcurrent Protection
Stable with 10-µF Ceramic Capacitors
Available in 7-pin TO-220, 7-Pin DDPAK/TO-263,
and 8-Pin SO PowerPAD™ Packages
−40°C to +125°C Operating Junction Temperature
Range
The fast transient response of this device makes it
suitable for use in powering DSP, microcontroller core
voltages, and switch-mode power supply postregulators.
Dropout Voltage: 130 mV (typical) at 1.5-A load
current.
2 Applications
•
•
•
•
ASIC Power Supplies In:
– Desktops, Notebooks, and Graphics Cards,
Servers
– Gaming Set Top Boxes, Printers and Copiers
Server Core and I/O Supplies
DSP and FPGA Power Supplies
SMPS Post-Regulator
Low Ground Pin Current: 10 mA (typical) at 1.5-A
load current.
Soft Start: Programmable soft-start time.
Device Information(1)
PART
NUMBER
LP38852-ADJ
PACKAGE
BODY SIZE (NOM)
DDPAK/TO-263 (7)
10.10 mm × 8.89 mm
TO-220 (7)
14.986 × 10.16 mm
SO PowerPAD (8)
4.89 mm × 3.90 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Typical Application Circuit
LP38852-ADJ
VIN
IN
VBIAS
VOUT
OUT
CIN
CFF
10 PF Ceramic
BIAS
R1
CBIAS
VEN
1 PF
SS
COUT
10 PF
Ceramic
ADJ
EN
R2
GND
CSS
GND
GND
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
LP38852-ADJ
SNVS482F – JANUARY 2007 – REVISED DECEMBER 2015
www.ti.com
Table of Contents
1
2
3
4
5
6
7
Features ..................................................................
Applications ...........................................................
Description .............................................................
Revision History.....................................................
Pin Configuration and Functions .........................
Specifications.........................................................
1
1
1
2
3
4
6.1
6.2
6.3
6.4
6.5
6.6
6.7
4
4
4
5
5
6
7
Absolute Maximum Ratings ......................................
ESD Ratings..............................................................
Recommended Operating Conditions.......................
Thermal Information ..................................................
Electrical Characteristics...........................................
Timing Requirements ................................................
Typical Characteristics ..............................................
Detailed Description ............................................ 11
7.1 Overview ................................................................. 11
7.2 Functional Block Diagram ....................................... 11
7.3 Feature Description................................................. 11
7.4 Device Functional Modes........................................ 14
8
Application and Implementation ........................ 15
8.1 Application Information............................................ 15
8.2 Typical Application ................................................. 15
9 Power Supply Recommendations...................... 19
10 Layout................................................................... 19
10.1 Layout Guidelines ................................................. 19
10.2 Layout Examples................................................... 20
11 Device and Documentation Support ................. 21
11.1
11.2
11.3
11.4
11.5
Documentation Support ........................................
Community Resources..........................................
Trademarks ...........................................................
Electrostatic Discharge Caution ............................
Glossary ................................................................
21
21
21
21
21
12 Mechanical, Packaging, and Orderable
Information ........................................................... 21
4 Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
Changes from Revision E (April 2013) to Revision F
Page
•
Added Device Information and Pin Configuration and Functions sections, ESD Ratings and Thermal Information
tables, Feature Description, Device Functional Modes, Application and Implementation, Power Supply
Recommendations, Layout, Device and Documentation Support, and Mechanical, Packaging, and Orderable
Information sections................................................................................................................................................................ 1
•
Deleted Lead temperature from Abs Max table; it is in POA ................................................................................................ 4
•
Updated thermal information ................................................................................................................................................. 5
•
Deleted out-of-date heatsinking subsections ....................................................................................................................... 17
Changes from Revision D (April 2013) to Revision E
•
2
Page
Changed layout of National Data Sheet to TI format ........................................................................................................... 19
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Copyright © 2007–2015, Texas Instruments Incorporated
Product Folder Links: LP38852-ADJ
LP38852-ADJ
www.ti.com
SNVS482F – JANUARY 2007 – REVISED DECEMBER 2015
5 Pin Configuration and Functions
KTW Package
7-Pin DDPAK/TO-263
Top View
TAB
IS
GND
SS
EN
IN
GND
ADJ
OUT
BIAS
1
2
3
4
5
6
7
LP38852T-ADJ
1
2
3
4
5
6
7
LP38852S-ADJ
SS
EN
IN
GND
ADJ
OUT
BIAS
NDZ Package
7-Pin TO-220
Top View
TAB
IS
GND
DDA Package
8-Pin SO PowerPAD
Top View
ADJ 1
8 N/C
OUT 2
7 IN
BIAS 3
6 EN
GND 4
5 SS
DAP
Connect to GND
Pin Functions
PIN
NAME
TYPE
DESCRIPTION
DDPAK/TO-263
TO-220
SO PowerPAD
ADJ
5
5
1
O
The feedback connection to set the output voltage
BIAS
7
7
3
I
The supply for the internal control and reference circuitry.
EN
2
2
6
I
Device enable, High = On, Low = Off.
GND
4
4
4
GND
IN
3
3
7
I
N/C
-
-
8
—
No internal connection
OUT
6
6
2
O
The regulated output voltage
SS
1
1
5
O
Soft-start capacitor connection. Used to control the rise time
of VOUT at turnon.
TAB
TAB
TAB
—
—
The KTW and NDZ TAB is a thermal and electrical
connection that is physically attached to the backside of the
die, and used as a thermal heat-sink connection.
DAP
—
—
DAP
—
The SO PowerPAD DAP is a thermal connection only that is
physically attached to the backside of the die, and used as a
thermal heat-sink connection.
Ground
The unregulated voltage input
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LP38852-ADJ
SNVS482F – JANUARY 2007 – REVISED DECEMBER 2015
www.ti.com
6 Specifications
6.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted) (1) (2)
MIN
MAX
UNIT
VIN supply voltage (survival)
−0.3
6
V
VBIAS supply voltage (survival)
−0.3
6
V
VSS soft-start voltage (survival)
−0.3
6
V
VOUT voltage (survival)
−0.3
6
V
IOUT current (survival)
Internally Limited
−40
Junction temperature
Power dissipation (3)
−65
Storage temperature, Tstg
(1)
(2)
(3)
150
°C
Internally Limited
150
°C
Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended
Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
If Military/Aerospace specified devices are required, contact the TI Sales Office/ Distributors for availability and specifications.
Device power dissipation must be de-rated based on device power dissipation (PD), ambient temperature (TA), and package junction to
ambient thermal resistance (RθJA). Additional heat-sinking may be required to ensure that the device junction temperature (TJ) does not
exceed the maximum operating rating. See the Application and Implementation section for details.
6.2 ESD Ratings
V(ESD)
(1)
Electrostatic discharge
Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001
(1)
VALUE
UNIT
±2000
V
JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
6.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted)
MIN
VIN supply voltage (survival)
NOM
MAX
UNIT
(VOUT + VDO) to VBIAS
V
0.8 V ≤ VOUT ≤ 1.2 V
3
5.5
V
1.2 V < VOUT ≤ 1.8 V
4.5
5.5
V
VEN voltage
0
VBIAS
IOUT
0
3
mA
−40
125
°C
VBIAS supply voltage (survival) (1)
Junction temperature (2)
(1)
(2)
4
V
VIN cannot exceed either VBIAS or 4.5 V, whichever value is lower.
Device power dissipation must be de-rated based on device power dissipation (PD), ambient temperature (TA), and package junction-toambient thermal resistance (RθJA). Additional heat sinking may be required to ensure that the device junction temperature (TJ) does not
exceed the maximum operating rating. See the Application and Implementation section for details.
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SNVS482F – JANUARY 2007 – REVISED DECEMBER 2015
6.4 Thermal Information
LP38852-ADJ
THERMAL METRIC (1)
KTW (DDPAK/TO-263)
NDZ (TO-220)
DDA (SO PowerPAD)
7 PINS
7 PINS
8 PINS
UNIT
RθJA
Junction-to-ambient thermal resistance
34.3
34.0
48.4
°C/W
RθJC(top)
Junction-to-case (top) thermal resistance
37.6
36.4
54.6
°C/W
RθJB
Junction-to-board thermal resistance
25.3
25.0
29.1
°C/W
ψJT
Junction-to-top characterization parameter
6.6
6.3
9.6
°C/W
ψJB
Junction-to-board characterization parameter
24.0
23.6
29.0
°C/W
RθJC(bot)
Junction-to-case (bottom) thermal resistance
n/a
n/a
4.3
°C/W
(1)
For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application
report, SPRA953.
6.5 Electrical Characteristics
Unless otherwise specified: VOUT = 0.8 V, VIN = VOUT(NOM) + 1 V, VBIAS = 3 V, VEN = VBIAS, IOUT = 10 mA, CIN = COUT = 10 µF,
CBIAS = 1 µF, CSS = open; typical (TYP) limits are for TJ = 25°C only, and minimum (MIN) and maximum (MAX) limits apply
over the junction temperature (TJ) range of –40°C to +125°C. Minimum and maximum limits are specified through test,
design, or statistical correlation. Typical values represent the most likely parametric norm at TJ = 25°C, and are provided for
reference purposes only.
PARAMETER
VADJ
VADJ accuracy
MIN
TYP
MAX
VOUT(NOM)+1 V ≤ VIN ≤ VBIAS ≤ 4.5 V (1)
3 V ≤ VBIAS ≤ 5.5 V, 10 mA ≤ IOUT ≤ 1.5 A
TJ = 25°C
TEST CONDITIONS
492.5
500.
507.5
VOUT(NOM)+1 V ≤ VIN ≤ VBIAS ≤ 4.5 V (1)
3 V ≤ VBIAS ≤ 5.5 V, 10 mA ≤ IOUT ≤ 1.5 A
485
VOUT(NOM)+1 V ≤ VIN ≤ VBIAS ≤ 4.5 V (1)
3 V ≤ VBIAS ≤ 5.5 V,
10 mA ≤ IOUT ≤ 1.5 A,
0°C ≤ TJ ≤ +125°C
490
3 V ≤ VBIAS ≤ 5.5 V
0.8
1.2
4.5 V ≤ VBIAS ≤ 5.5 V
0.8
1.8
515
500.
UNIT
mV
510
VOUT
VOUT range
ΔVOUT/ΔVIN
Line regulation, VIN (2)
VOUT(NOM)+1 V ≤ VIN ≤ VBIAS
0.04
%/V
ΔVOUT/ΔVBIAS
Line regulation, VBIAS (2)
3 V ≤ VBIAS ≤ 5.5 V
0.1
%/V
ΔVOUT/ΔIOUT
Output voltage load
regulation (3)
10 mA ≤ IOUT ≤ 1.5 A
0.2
%/A
VDO
Dropout voltage (4)
IOUT = 1.5 A, TJ = 25°C
130
IOUT = 1.5 A
VOUT = 0.8 V, VBIAS = 3 V
10 mA ≤ IOUT ≤ 1.5 A
TJ = 25°C
IGND(IN)
Quiescent current drawn from
VIN supply
180
7
IGND(BIAS)
Quiescent current drawn from
VBIAS supply
1
VEN ≤ 0.5 V
(1)
(2)
(3)
(4)
100
300
3
10 mA ≤ IOUT ≤ 1.5 A
VEN ≤ 0.5 V, TJ = 25°C
8.5
9
VEN ≤ 0.5 V
10 mA ≤ IOUT ≤ 1.5 A, TJ = 25°C
mV
mA
VOUT = 0.8 V, VBIAS = 3 V
10 mA ≤ IOUT ≤ 1.5 A
VEN ≤ 0.5 V, TJ = 25°C
165
V
3.8
4.5
100
170
200
μA
mA
μA
VIN cannot exceed either VBIAS or 4.5 V, whichever value is lower.
Output voltage line regulation is defined as the change in output voltage from nominal value resulting from a change in input voltage.
Output voltage load regulation is defined as the change in output voltage from nominal value as the load current increases from no load
to full load.
Dropout voltage is defined as the input to output voltage differential (VIN – VOUT) where the input voltage is low enough to cause the
output voltage to drop 2% from the nominal value.
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SNVS482F – JANUARY 2007 – REVISED DECEMBER 2015
www.ti.com
Electrical Characteristics (continued)
Unless otherwise specified: VOUT = 0.8 V, VIN = VOUT(NOM) + 1 V, VBIAS = 3 V, VEN = VBIAS, IOUT = 10 mA, CIN = COUT = 10 µF,
CBIAS = 1 µF, CSS = open; typical (TYP) limits are for TJ = 25°C only, and minimum (MIN) and maximum (MAX) limits apply
over the junction temperature (TJ) range of –40°C to +125°C. Minimum and maximum limits are specified through test,
design, or statistical correlation. Typical values represent the most likely parametric norm at TJ = 25°C, and are provided for
reference purposes only.
PARAMETER
UVLO
Undervoltage lockout threshold
TEST CONDITIONS
MIN
TYP
MAX
VBIAS rising until device is functional
TJ = 25°C
2.2
2.45
2.7
VBIAS rising until device is functional
2
VBIAS falling from UVLO threshold until
device is non-functional
Undervoltage lockout hysteresis TJ = 25°C
VBIAS falling from UVLO threshold until
device is non-functional
UVLO(HYS)
ISC
Output short-circuit current
60
UNIT
V
2.9
150
300
mV
50
VIN = VOUT(NOM) + 1 V, VBIAS = 3 V,
VOUT = 0 V
350
4.5
A
SOFT-START
rSS
Soft-start internal resistance
tSS
Soft-start time
tSS = CSS × rSS × 5
11
CSS = 10 nF
13.5
16
kΩ
μs
675
ENABLE
VEN = VBIAS
IEN
ENABLE pin current
VEN(ON)
Enable voltage threshold
VEN(HYS)
Enable voltage hysteresis
0.01
VEN = 0 V, VBIAS = 5.5 V, TJ = 25°C
–19
VEN = 0 V, VBIAS = 5.5 V
–13
VEN rising until output = ON, TJ = 25°C
1
VEN rising until output = ON
0.9
VEN falling from VEN(ON) until Output = OFF
TJ = 25°C
50
VEN falling from VEN(ON) until Output = OFF
30
–30
–40
μA
–51
1.25
1.5
1.55
100
150
V
mV
200
AC PARAMETERS
PSRR (VIN)
PSRR (VBIAS)
Ripple rejection for VIN input
voltage
Ripple rejection for VBIAS
voltage
Output noise density
en
Output noise voltage
VIN = VOUT(NOM) + 1 V,
ƒ = 120 Hz
80
VIN = VOUT(NOM) + 1 V,
ƒ = 1 kHz
65
VBIAS = VOUT(NOM) + 3 V,
ƒ= 120 Hz
58
VBIAS = VOUT(NOM) + 3 V,
ƒ = 1 kHz
58
dB
dB
ƒ = 120 Hz
1
BW = 10 Hz − 100 kHz
150
BW = 300 Hz − 300 kHz
90
µV/√Hz
µVRMS
THERMAL PARAMETERS
TSD
Thermal shutdown junction
temperature
TSD(HYS)
Thermal shutdown hysteresis
160
°C
10
°C
6.6 Timing Requirements
MIN
NOM
MAX
UNIT
tOFF
Turnoff delay time, RLOAD x COUT