TPS74801-Q1
www.ti.com
SLVSAI4B – OCTOBER 2010 – REVISED JULY 2013
1.5 A Low-Dropout Linear Regulator with Programmable Soft-Start
Check for Samples: TPS74801-Q1
FEATURES
APPLICATIONS
•
•
•
•
•
•
1
2
•
•
•
•
•
•
•
•
•
•
Qualified for Automotive Applications
AEC-Q100 Qualified with the Following
Results:
– Device Temperature Grade 1: –40°C to
125°C Ambient Operating Temperature
Range
– Device HBM ESD Classification Level H2
– Device HBM ESD Classification Level C4B
VOUT Range: 0.8 V to 3.6 V
Ultralow VIN Range: 0.8 V to 5.5 V
VBIAS Range 2.7 V to 5.5 V
Low Dropout: 60 mV typ at 1.5 A, VBIAS = 5 V
Power Good (PG) Output Allows Supply
Monitoring or Provides a Sequencing Signal
for Other Supplies
2% Accuracy Over Line/Load/Temperature
Programmable Soft-Start Provides Linear
Voltage Startup
VBIAS Permits Low VIN Operation with Good
Transient Response
Stable with Any Output Capacitor ≥ 2.2 μF
Available in a Small 3-mm x 3-mm x 1-mm
SON-10 and 5 x 5 QFN-20 Packages
•
FPGA Applications
DSP Core and I/O Voltages
Post-Regulation Applications
Applications with Special Start-Up Time or
Sequencing Requirements
Hot-Swap and Inrush Controls
DESCRIPTION
The TPS74801-Q1 low-dropout (LDO) linear regulator
provides an easy-to-use robust power management
solution for a wide variety of applications. Userprogrammable soft-start minimizes stress on the input
power source by reducing capacitive inrush current
on start-up. The soft-start is monotonic and wellsuited for powering many different types of
processors and ASICs. The enable input and power
good output allow easy sequencing with external
regulators. This complete flexibility permits the user to
configure a solution that meets the sequencing
requirements of FPGAs, DSPs, and other
applications with special start-up requirements.
A precision reference and error amplifier deliver 2%
accuracy over load, line, temperature, and process.
The device is stable with any type of capacitor
greater than or equal to 2.2 μF, and is fully specified
from –40°C to 105°C for the DRC package, and from
–40°C to 125°C for the RGW package. The
TPS74801-Q1 is offered in a small 3-mm × 3-mm
SON-10 package, yielding a highly compact, total
solution size. It is also available in a 5 x 5 QFN-20 for
compatibility with the TPS74401.
CSS = 0nF
VIN
IN
CIN
PG
EN
VBIAS
TPS74801
R1
GND
CSS
VOUT
CSS = 2.2nF
VOUT
OUT
SS
CBIAS
CSS = 1nF
0.5V/div
R3
BIAS
COUT
FB
R2
1.2V
1V/div
VEN
0V
Time (1ms/div)
Figure 1. Typical Application Circuit (Adjustable)
Figure 2. Turn-On Response
1
2
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.
All trademarks are the property of their respective owners.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2010–2013, Texas Instruments Incorporated
TPS74801-Q1
SLVSAI4B – OCTOBER 2010 – REVISED JULY 2013
www.ti.com
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with
appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more
susceptible to damage because very small parametric changes could cause the device not to meet its published specifications.
ABSOLUTE MAXIMUM RATINGS (1)
At TA = –40°C to 105°C (for TPS74801TDRCRQ1), TA = –40°C to 125°C (for TPS74801QRGWRQ1), unless otherwise noted.
All voltages are with respect to GND.
TPS74801-Q1
UNIT
VIN, VBIAS
Input voltage range
–0.3 to 6
V
VEN
Enable voltage range
–0.3 to 6
V
VPG
Power good voltage range
–0.3 to 6
V
IPG
PG sink current
0 to 1.5
mA
VSS
Soft-start voltage range
–0.3 to 6
V
VFB
Feedback voltage range
–0.3 to 6
V
VOUT
Output voltage range
–0.3 to VIN + 0.3
V
IOUT
Maximum output current
Internally limited
Output short-circuit duration
Indefinite
PDISS
Continuous total power dissipation
TJ
Operating junction temperature range
–40 to 150
°C
TSTG
Storage junction temperature range
–55 to 150
°C
Electrostatic
Discharge
(ESD) Ratings
Human body model (HBM) classification level H2
2000
V
Charged device model (CDM) classification level C4B
750
V
(1)
2
See Thermal Information Table
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 conditions is not implied. Exposure to absolute-maximum-rated conditions for
extended periods may affect device reliability.
Submit Documentation Feedback
Copyright © 2010–2013, Texas Instruments Incorporated
Product Folder Links: TPS74801-Q1
TPS74801-Q1
www.ti.com
SLVSAI4B – OCTOBER 2010 – REVISED JULY 2013
THERMAL INFORMATION
TPS74801-Q1 (2)
THERMAL METRIC
(1)
Junction-to-ambient thermal resistance (3)
θJA
(4)
RGW
DRC
20 PINS
10 PINS
35.6
41.5
θJCtop
Junction-to-case (top) thermal resistance
33.3
78
θJB
Junction-to-board thermal resistance (5)
15
N/A
ψJT
Junction-to-top characterization parameter (6)
0.4
0.7
ψJB
Junction-to-board characterization parameter (7)
15.2
11.3
θJCbot
Junction-to-case (bottom) thermal resistance (8)
3.8
6.6
(1)
(2)
UNIT
°C/W
For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953A.
Thermal data for the RGW and DRC packages are derived by thermal simulations based on JEDEC-standard methodology as specified
in the JESD51 series. The following assumptions are used in the simulations:
(a) i. RGW: The exposed pad is connected to the PCB ground layer through a 4x4 thermal via array.
MMii. DRC: The exposed pad is connected to the PCB ground layer through a 3x2 thermal via array.
(b) i. RGW: Each of top and bottom copper layers has a dedicated pattern for 20% copper coverage.
MMii. DRC: The top and bottom copper layers are assumed to have a 20% thermal conductivity of copper representing a 20%
MMcopper coverage.
(3)
(4)
(5)
(6)
(7)
(8)
(c) This data was generated with only a single device at the center of a JEDEC high-K (2s2p) board with 3-in × 3-in copper area.
To understand the effects of the copper area on thermal performance, see the Power Dissipation and Estimating Junction
Temperature sections of this data sheet.
The junction-to-ambient thermal resistance under natural convection is obtained in a simulation on a JEDEC-standard, high-K board, as
specified in JESD51-7, in an environment described in JESD51-2a.
The junction-to-case (top) thermal resistance is obtained by simulating a cold plate test on the top of the package. No specific JEDECstandard test exists, but a close description can be found in the ANSI SEMI standard G30-88.
The junction-to-board thermal resistance is obtained by simulating in an environment with a ring cold plate fixture to control the PCB
temperature, as described in JESD51-8.
The junction-to-top characterization parameter, ψJT, estimates the junction temperature of a device in a real system and is extracted
from the simulation data to obtain θJA using a procedure described in JESD51-2a (sections 6 and 7).
The junction-to-board characterization parameter, ψJB, estimates the junction temperature of a device in a real system and is extracted
from the simulation data to obtain θJA using a procedure described in JESD51-2a (sections 6 and 7).
The junction-to-case (bottom) thermal resistance is obtained by simulating a cold plate test on the exposed (power) pad. No specific
JEDEC standard test exists, but a close description can be found in the ANSI SEMI standard G30-88.
Submit Documentation Feedback
Copyright © 2010–2013, Texas Instruments Incorporated
Product Folder Links: TPS74801-Q1
3
TPS74801-Q1
SLVSAI4B – OCTOBER 2010 – REVISED JULY 2013
www.ti.com
ELECTRICAL CHARACTERISTICS
At VEN = 1.1 V, VIN = VOUT + 0.3 V, CBIAS = 0.1 μF, CIN = COUT = 10 μF, CNR = 1 nF, IOUT = 50 mA, VBIAS = 5 V, TA = –40°C to
105°C (DRC) and TA = –40°C to 125°C (RGW), unless otherwise noted. Typical values are at TA = 25°C.
TPS74801-Q1
PARAMETER
TEST CONDITIONS
VIN
Input voltage range
VBIAS
Bias pin voltage range
VREF
Internal reference (Adj.)
VOUT
MIN
MAX
UNIT
VOUT + VDO
5.5
V
2.7
5.5
V
0.804
V
3.6
V
2
%
TA = 25°C
0.796
Output voltage range
VIN = 5 V, IOUT = 1.5 A
VREF
Accuracy (1)
2.97 V ≤ VBIAS ≤ 5.5 V,
50 mA ≤ IOUT ≤ 1.5 A
–2
TYP
0.8
±0.5
VOUT (NOM) + 0.3 ≤ VIN ≤ 5.5 V
0.03
50 mA ≤ IOUT ≤ 1.5 A
0.09
IOUT = 1.5 A,
VBIAS – VOUT (NOM) ≥ 3.25 V (3)
60
165
mV
VBIAS dropout voltage (2)
IOUT = 1.5 A, VIN = VBIAS
1.31
1.6
V
ICL
Current limit
VOUT = 80% × VOUT (NOM)
IBIAS
Bias pin current
ISHDN
Shutdown supply current
(IGND)
IFB
Feedback pin current
VOUT/VIN
Line regulation
VOUT/IOUT
Load regulation
VIN dropout voltage
VDO
(2)
Power-supply rejection
(VIN to VOUT)
PSRR
Power-supply rejection
(VBIAS to VOUT)
2.0
VEN ≤ 0.4 V
–1
%/V
%/A
5.5
A
1
2
mA
1
50
μA
0.150
1
μA
1 kHz, IOUT = 1.5 A,
VIN = 1.8 V, VOUT = 1.5 V
60
300 kHz, IOUT = 1.5 A,
VIN = 1.8 V, VOUT = 1.5 V
30
1 kHz, IOUT = 1.5 A,
VIN = 1.8 V, VOUT = 1.5 V
50
300 kHz, IOUT = 1.5 A,
VIN = 1.8 V, VOUT = 1.5 V
30
dB
dB
Noise
Output noise voltage
100 Hz to 100 kHz,
IOUT = 1.5 A, CSS = 0.001 μF
25 × VOUT
tSTR
Minimum startup time
RLOAD for IOUT = 1 A, CSS = open
200
μs
ISS
Soft-start charging current
VSS = 0.4 V
440
nA
μVRMS
VEN,
HI
Enable input high level
1.1
5.5
VEN,
LO
Enable input low level
0
0.4
VEN,
HYS
Enable pin hysteresis
50
mV
VEN,
DG
Enable pin deglitch time
20
μs
1
μA
90
94
%VOUT
Enable pin current
VIT
PG trip threshold
VHYS
PG trip hysteresis
VPG, LO
PG output low voltage
IPG, LKG
PG leakage current
VPG = 5.25 V, VOUT > VIT
0.1
TSD
Thermal shutdown
temperature
Shutdown, temperature increasing
165
Reset, temperature decreasing
140
(1)
(2)
(3)
4
VEN = 5 V
85
V
0.1
IEN
VOUT decreasing
V
3
IPG = 1 mA (sinking), VOUT < VIT
%VOUT
0.3
V
1
μA
°C
Adjustable devices tested at 0.8 V; resistor tolerance is not taken into account.
Dropout is defined as the voltage from VIN to VOUT when VOUT is 3% below nominal.
3.25 V is a test condition of this device and can be adjusted by referring to Figure 8.
Submit Documentation Feedback
Copyright © 2010–2013, Texas Instruments Incorporated
Product Folder Links: TPS74801-Q1
TPS74801-Q1
www.ti.com
SLVSAI4B – OCTOBER 2010 – REVISED JULY 2013
BLOCK DIAGRAM
IN
Current
Limit
BIAS
UVLO
OUT
Thermal
Limit
0.44mA
VOUT
R1
SS
CSS
Soft-Start
Discharge
0.8V
Reference
FB
PG
EN
Hysteresis
and Deglitch
R2
0.9 ´ VREF
GND
Table 1. Standard 1% Resistor Values for Programming the Output Voltage (1)
(1)
R1 (kΩ)
R2 (kΩ)
VOUT (V)
Short
Open
0.8
0.619
4.99
0.9
1.13
4.53
1
1.37
4.42
1.05
1.87
4.99
1.1
2.49
4.99
1.2
4.12
4.75
1.5
3.57
2.87
1.8
3.57
1.69
2.5
3.57
1.15
3.3
VOUT = 0.8 × (1 + R1 / R2).
Table 2. Standard Capacitor Values for Programming the Soft-Start Time (1)
(1)
CSS
SOFT-START TIME
Open
0.1 ms
270 pF
0.5 ms
560 pF
1 ms
2.7 nF
5 ms
5.6 nF
10 ms
0.01 μF
18 ms
–7
tSS(s) = 0.8 × CSS(F) / 4.4 × 10 .
DEVICE INFORMATION
Submit Documentation Feedback
Copyright © 2010–2013, Texas Instruments Incorporated
Product Folder Links: TPS74801-Q1
5
TPS74801-Q1
SLVSAI4B – OCTOBER 2010 – REVISED JULY 2013
www.ti.com
NC
NC
NC
OUT
4
3
2
1
IN
6
20
OUT
IN
7
19
OUT
IN
8
18
OUT
PG
9
17
NC
BIAS
10
16
FB
13
14
15
NC
SS
TPS74801
GND
NC
EN 5
8 FB
7 SS
6 GND
12
BIAS 4
GND
Thermal
Pad
11
PG 3
IN
10 OUT
9 OUT
IN 2
EN
IN 1
RGW PACKAGE
5 x 5 QFN
(TOP VIEW)
5
DRC PACKAGE
3-mm x 3-mm SON
(TOP VIEW)
PIN DESCRIPTIONS
6
NAME
DRC (SON)
RGW (QFN)
IN
1, 2
5-8
DESCRIPTION
Input to the device.
EN
5
11
Enable pin. Driving this pin high enables the regulator. Driving this pin low puts
the regulator into shutdown mode. This pin must not be left unconnected.
SS
7
15
Soft-Start pin. A capacitor connected on this pin to ground sets the start-up time.
If this pin is left unconnected, the regulator output soft-start ramp time is typically
200 μs.
BIAS
4
10
Bias input voltage for error amplifier, reference, and internal control circuits.
PG
3
9
Power Good pin. An open-drain, active-high output that indicates the status of
VOUT. When VOUT exceeds the PG trip threshold, the PG pin goes into a highimpedance state. When VOUT is below this threshold the pin is driven to a lowimpedance state. A pull-up resistor from 10 kΩ to 1 MΩ should be connected
from this pin to a supply of up to 5.5 V. The supply can be higher than the input
voltage. Alternatively, the PG pin can be left unconnected if output monitoring is
not necessary.
FB
8
16
Feedback pin. The feedback connection to the center tap of an external resistor
divider network that sets the output voltage. This pin must not be left floating.
OUT
9, 10
1, 18-20
Regulated output voltage. A small capacitor (total typical capacitance ≥ 2.2 μF,
ceramic) is needed from this pin to ground to assure stability.
NC
N/A
2-4, 13, 14, 17
No connection. This pin can be left floating or connected to GND to allow better
thermal contact to the top-side plane.
GND
6
12
Thermal Pad
—
Ground
Should be soldered to the ground plane for increased thermal performance.
Submit Documentation Feedback
Copyright © 2010–2013, Texas Instruments Incorporated
Product Folder Links: TPS74801-Q1
TPS74801-Q1
www.ti.com
SLVSAI4B – OCTOBER 2010 – REVISED JULY 2013
TYPICAL CHARACTERISTICS
At TA = 25°C, VIN = VOUT(TYP) + 0.3 V, VBIAS = 5 V, IOUT = 50 mA, VEN = VIN, CIN = 1 μF, CBIAS = 4.7 μF, and COUT = 10 μF,
unless otherwise noted.
VIN LINE REGULATION
0.20
0.4
0.15
0.3
0.10
Change in VOUT (%)
Change in VOUT (%)
VBIAS LINE REGULATION
0.5
-40°C
0.05
0
+25°C
-0.05
+125°C
-0.01
0.2
-40°C
0.1
0
-0.1
+125°C
-0.2
+25°C
-0.3
-0.15
-0.4
-0.20
-0.5
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
0.5
5.0
1.0
1.5
2.0
2.5
3.0
VIN - VOUT (V)
VBIAS - VOUT (V)
Figure 3.
Figure 4.
LOAD REGULATION
3.5
4.0
LOAD REGULATION
1.2
0.5
0.4
0.3
Change in VOUT (%)
Change in VOUT (%)
1.0
0.8
0.6
0.4
0.2
+125°C
0.1
0
-40°C
+25°C
-0.1
-0.2
-0.3
0.2
-0.4
0
0
10
20
30
40
-0.5
0.05
50
0.5
1.0
IOUT (mA)
Figure 5.
Figure 6.
VIN DROPOUT VOLTAGE vs
IOUT AND TEMPERATURE (TA)
100
IOUT = 1.5A
180
80
+125°C
70
VDO (VIN - VOUT) (mV)
VDO (VIN - VOUT) (mV)
VIN DROPOUT VOLTAGE vs
(VBIAS – VOUT) AND TEMPERATURE (TA)
200
90
60
50
40
+25°C
30
20
160
140
120
+125°C
100
+25°C
80
60
40
-40°C
10
1.5
IOUT (A)
-40°C
20
0
0
0
0.5
1.0
1.5
1.0
IOUT (A)
1.5
2.0
2.5
3.0
3.5
4.0
4.5
VBIAS - VOUT (V)
Figure 7.
Figure 8.
Submit Documentation Feedback
Copyright © 2010–2013, Texas Instruments Incorporated
Product Folder Links: TPS74801-Q1
7
TPS74801-Q1
SLVSAI4B – OCTOBER 2010 – REVISED JULY 2013
www.ti.com
TYPICAL CHARACTERISTICS (continued)
At TA = 25°C, VIN = VOUT(TYP) + 0.3 V, VBIAS = 5 V, IOUT = 50 mA, VEN = VIN, CIN = 1 μF, CBIAS = 4.7 μF, and COUT = 10 μF,
unless otherwise noted.
VIN DROPOUT VOLTAGE vs
(VBIAS – VOUT) AND TEMPERATURE (TA)
200
2000
160
VDO (VBIAS - VOUT) (mV)
VDO (VIN - VOUT) (mV)
2200
IOUT = 0.5A
180
VBIAS DROPOUT VOLTAGE vs
IOUT AND TEMPERATURE (TA)
140
120
100
+25°C
80
+125°C
60
40
-40°C
1800
1600
+125°C
1400
1200
+25°C
1000
-40°C
800
20
600
0
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
0
4.5
0.5
VBIAS - VOUT (V)
Figure 9.
70
60
50
40
IOUT = 0.5A
30
VIN = 1.8V
VOUT = 1.2V
VBIAS = 5V
CSS = 1nF
20
10
0
10
100
1k
70
10k
100k
1M
40
30
20
VIN = 1.8V
VOUT = 1.2V
CSS = 1nF
10
10
1k
10k
Figure 12.
1kHz
40
100kHz
30
20
500kHz
10
0.75
1.00
1.25
1.50
100k
1M
10M
NOISE SPECTRAL DENSITY
10kHz
0.50
100
IOUT = 1.5A
Figure 11.
0
8
50
Frequency (Hz)
50
0.25
IOUT = 100mA
60
10M
60
0
70
Frequency (Hz)
VOUT = 1.2V
IOUT = 1.5A
CSS = 1nF
80
80
0
VIN PSRR vs (VIN – VOUT)
90
Power-Supply Rejection Ratio (dB)
IOUT = 1.5A
Power-Supply Rejection Ratio (dB)
IOUT = 0.1A
VIN PSRR vs FREQUENCY
90
1.75
2.00 2.25
Output Spectral Noise Density (mV/ÖHz)
Power-Supply Rejection Ratio (dB)
80
1.5
Figure 10.
VBIAS PSRR vs FREQUENCY
90
1.0
IOUT (A)
1
IOUT = 100mA
VOUT = 1.2V
CSS = 0nF
0.1
CSS = 10nF
CSS = 1nF
0.01
100
1k
10k
VIN - VOUT (V)
Frequency (Hz)
Figure 13.
Figure 14.
Submit Documentation Feedback
100k
Copyright © 2010–2013, Texas Instruments Incorporated
Product Folder Links: TPS74801-Q1
TPS74801-Q1
www.ti.com
SLVSAI4B – OCTOBER 2010 – REVISED JULY 2013
TYPICAL CHARACTERISTICS (continued)
At TA = 25°C, VIN = VOUT(TYP) + 0.3 V, VBIAS = 5 V, IOUT = 50 mA, VEN = VIN, CIN = 1 μF, CBIAS = 4.7 μF, and COUT = 10 μF,
unless otherwise noted.
BIAS PIN CURRENT vs
IOUT AND TEMPERATURE (TA)
2.0
1.8
2.0
1.8
+125°C
1.6
+125°C
1.6
1.4
1.4
IBIAS (mA)
IBIAS (mA)
BIAS PIN CURRENT vs
VBIAS AND TEMPERATURE (TA)
1.2
1.0
0.8
+25°C
-40°C
0.6
1.2
+25°C
1.0
0.8
0.6
0.4
0.4
0.2
0.2
0
-40°C
0
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
2.0
1.6
2.5
3.0
3.5
IOUT (A)
Figure 15.
5.0
5.5
LOW-LEVEL PG VOLTAGE vs CURRENT
1.0
VOL Low-Level PG Voltage (V)
475
450
ISS (nA)
4.5
Figure 16.
SOFT-START CHARGING CURRENT (ISS) vs
TEMPERATURE (TA)
500
4.0
VBIAS (V)
425
400
375
350
325
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
300
-50
-25
0
25
50
75
100
125
0
2
4
Ambient Temperature (°C)
8
10
12
PG Current (mA)
Figure 17.
Figure 18.
CURRENT LIMIT vs (VBIAS – VOUT)
4.0
VOUT = 0.8V
3.8
+125°C
3.6
Current Limit (A)
6
3.4
3.2
3.0
-40°C
2.8
+25°C
2.6
2.4
2.2
2.0
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
VBIAS - VOUT (V)
Figure 19.
Submit Documentation Feedback
Copyright © 2010–2013, Texas Instruments Incorporated
Product Folder Links: TPS74801-Q1
9
TPS74801-Q1
SLVSAI4B – OCTOBER 2010 – REVISED JULY 2013
www.ti.com
TYPICAL CHARACTERISTICS
At TA = 25°C, VIN = VOUT(TYP) + 0.3 V, VBIAS = 5 V, IOUT = 1 A, VEN = VIN = 1.8 V, VOUT = 1.5 V, CIN = 1 μF, CBIAS = 4.7 μF, and
COUT = 10 μF, unless otherwise noted.
VBIAS LINE TRANSIENT
VIN LINE TRANSIENT
CSS = 1nF
COUT = 10mF (Ceramic)
COUT = 10mF (Ceramic)
100mV/div
100mV/div
COUT = 2.2mF (Ceramic)
100mV/div
CSS = 1nF
3.8V
5.0V
1V/div
1V/div
1V/ms
3.3V
1V/ms
1.8V
Time (50ms/div)
Time (50ms/div)
Figure 20.
Figure 21.
OUTPUT LOAD TRANSIENT RESPONSE
TURN-ON RESPONSE
COUT = 470mF (OSCON)
CSS = 0nF
100mV/div
COUT = 10mF (Ceramic)
100mV/div
CSS = 1nF
0.5V/div
VOUT
CSS = 2.2nF
COUT = 2.2mF (Ceramic)
100mV/div
1.2V
1.5A
CSS = 1nF
1A/div
1V/div
VEN
0V
1A/ms
50mA
Time (50ms/div)
Time (1ms/div)
Figure 22.
Figure 23.
POWER-UP/POWER-DOWN
VIN = VBIAS = VEN
1V/div
VPG (500mV/div)
VOUT
Time (20ms/div)
Figure 24.
10
Submit Documentation Feedback
Copyright © 2010–2013, Texas Instruments Incorporated
Product Folder Links: TPS74801-Q1
TPS74801-Q1
www.ti.com
SLVSAI4B – OCTOBER 2010 – REVISED JULY 2013
APPLICATION INFORMATION
The TPS74801-Q1 belongs to a family of low dropout regulators that feature soft-start capability. These
regulators use a low current bias input to power all internal control circuitry, allowing the NMOS pass transistor to
regulate very low input and output voltages.
The use of an NMOS-pass FET offers several critical advantages for many applications. Unlike a PMOS topology
device, the output capacitor has little effect on loop stability. This architecture allows the TPS74801-Q1 to be
stable with any capacitor type of value 2.2 μF or greater. Transient response is also superior to PMOS
topologies, particularly for low VIN applications.
The TPS74801-Q1 features a programmable voltage-controlled soft-start circuit that provides a smooth,
monotonic start-up and limits startup inrush currents that may be caused by large capacitive loads. A power good
(PG) output is available to allow supply monitoring and sequencing of other supplies. An enable (EN) pin with
hysteresis and deglitch allows slow-ramping signals to be used for sequencing the device. The low VIN and VOUT
capability allows for inexpensive, easy-to-design, and efficient linear regulation between the multiple supply
voltages often present in processor-intensive systems.
Figure 25 illustrates the typical application circuit for the TPS74801-Q1 adjustable output device.
VIN
IN
CIN
1mF
PG
R3
BIAS
EN
VBIAS
TPS74801
R1
SS
CBIAS
1mF
VOUT
OUT
FB
GND
CSS
COUT
10mF
R2
(
VOUT = 0.8 ´ 1 +
R1
R2
)
Figure 25. Typical Application Circuit for the TPS74801-Q1 (Adjustable)
R1 and R2 can be calculated for any output voltage using the formula shown in Figure 25. Refer to Table 1 for
sample resistor values of common output voltages. In order to achieve the maximum accuracy specifications, R2
should be ≤ 4.99 kΩ.
INPUT, OUTPUT, AND BIAS CAPACITOR REQUIREMENTS
The device is designed to be stable for all available types and values of output capacitors ≥ 2.2 μF. The device is
also stable with multiple capacitors in parallel, which can be of any type or value.
The capacitance required on the IN and BIAS pins strongly depends on the input supply source impedance. To
counteract any inductance in the input, the minimum recommended capacitor for VIN and VBIAS is 1 μF. If VIN and
VBIAS are connected to the same supply, the recommended minimum capacitor for VBIAS is 4.7 μF. Good quality,
low ESR capacitors should be used on the input; ceramic X5R and X7R capacitors are preferred. These
capacitors should be placed as close the pins as possible for optimum performance.
TRANSIENT RESPONSE
The TPS74801-Q1 was designed to have excellent transient response for most applications with a small amount
of output capacitance. In some cases, the transient response may be limited by the transient response of the
input supply. This limitation is especially true in applications where the difference between the input and output is
less than 300 mV. In this case, adding additional input capacitance improves the transient response much more
than just adding additional output capacitance would do. With a solid input supply, adding additional output
capacitance reduces undershoot and overshoot during a transient event; refer to Figure 22 in the Typical
Submit Documentation Feedback
Copyright © 2010–2013, Texas Instruments Incorporated
Product Folder Links: TPS74801-Q1
11
TPS74801-Q1
SLVSAI4B – OCTOBER 2010 – REVISED JULY 2013
www.ti.com
Characteristics section. Because the TPS74801-Q1 is stable with output capacitors as low as 2.2 μF, many
applications may then need very little capacitance at the LDO output. For these applications, local bypass
capacitance for the powered device may be sufficient to meet the transient requirements of the application. This
design reduces the total solution cost by avoiding the need to use expensive, high-value capacitors at the LDO
output.
DROPOUT VOLTAGE
The TPS74801-Q1 offers very low dropout performance, making it well-suited for high-current, low VIN / low VOUT
applications. The low dropout of the TPS74801-Q1 allows the device to be used in place of a DC-DC converter
and still achieve good efficiency. This provides designers with the power architecture for their application to
achieve the smallest, simplest, and lowest cost solution.
There are two different specifications for dropout voltage with the TPS74801-Q1. The first specification (shown in
Figure 26) is referred to as VIN Dropout and is used when an external bias voltage is applied to achieve low
dropout. This specification assumes that VBIAS is at least 3.25 V (1) above VOUT, which is the case for VBIAS when
powered by a 5-V rail with 5% tolerance and with VOUT = 1.5 V. If VBIAS is higher than VOUT 3.25 V (1), VIN dropout
is less than specified.
BIAS
IN
Reference
VBIAS = 5V ±5%
VIN = 1.8V
VOUT = 1.5V
IOUT = 1.5A
Efficiency = 83%
OUT
VOUT
COUT
FB
Simplified Block Diagram
Figure 26. Typical Application of the TPS74801-Q1 Using an Auxiliary Bias Rail
VIN
BIAS
Reference
IN
VBIAS = 3.3V ±5%
VIN = 3.3V ± 5V
VOUT = 1.5V
IOUT = 1.5A
Efficiency = 45%
OUT
VOUT
COUT
FB
Simplified Block Diagram
Figure 27. Typical Application of the TPS74801-Q1 Without an Auxiliary Bias Rail
The second specification (shown in Figure 27) is referred to as VBIAS Dropout and applies to applications where
IN and BIAS are tied together. This option allows the device to be used in applications where an auxiliary bias
voltage is not available or low dropout is not required. Dropout is limited by BIAS in these applications because
VBIAS provides the gate drive to the pass FET; therefore, VBIAS must be 1.6 V above VOUT. Because of this usage,
IN and BIAS tied together easily consume huge power. Pay attention not to exceed the power rating of the IC
package.
(1)
12
3.25 V is a test condition of this device and can be adjusted by referring to Figure 8.
Submit Documentation Feedback
Copyright © 2010–2013, Texas Instruments Incorporated
Product Folder Links: TPS74801-Q1
TPS74801-Q1
www.ti.com
SLVSAI4B – OCTOBER 2010 – REVISED JULY 2013
PROGRAMMABLE SOFT-START
The TPS74801-Q1 features a programmable, monotonic, voltage-controlled soft-start that is set with an external
capacitor (CSS). This feature is important for many applications because it eliminates power-up initialization
problems when powering FPGAs, DSPs, or other processors. The controlled voltage ramp of the output also
reduces peak inrush current during start-up, minimizing start-up transient events to the input power bus.
To achieve a linear and monotonic soft-start, the TPS74801-Q1 error amplifier tracks the voltage ramp of the
external soft-start capacitor until the voltage exceeds the internal reference. The soft-start ramp time depends on
the soft-start charging current (ISS), soft-start capacitance (CSS), and the internal reference voltage (VREF), and
can be calculated using Equation 1:
(VREF ´ CSS)
tSS =
ISS
(1)
If large output capacitors are used, the device current limit (ICL) and the output capacitor may set the start-up
time. In this case, the start-up time is given by Equation 2:
(VOUT(NOM) ´ COUT)
tSSCL =
ICL(MIN)
(2)
where:
VOUT(NOM) is the nominal output voltage,
COUT is the output capacitance, and
ICL(MIN) is the minimum current limit for the device.
In applications where monotonic startup is required, the soft-start time given by Equation 1 should be set greater
than Equation 2.
The maximum recommended soft-start capacitor is 0.015 μF. Larger soft-start capacitors can be used and do not
damage the device; however, the soft-start capacitor discharge circuit may not be able to fully discharge the softstart capacitor when enabled. Soft-start capacitors larger than 0.015 μF could be a problem in applications where
it is necessary to rapidly pulse the enable pin and still require the device to soft-start from ground. CSS must be
low-leakage; X7R, X5R, or C0G dielectric materials are preferred. Refer to Table 2 for suggested soft-start
capacitor values.
SEQUENCING REQUIREMENTS
VIN, VBIAS, and VEN can be sequenced in any order without causing damage to the device. However, for the softstart function to work as intended, certain sequencing rules must be applied. Connecting EN to IN is acceptable
for most applications, as long as VIN is greater than 1.1 V and the ramp rate of VIN and VBIAS is faster than the
set soft-start ramp rate. If the ramp rate of the input sources is slower than the set soft-start time, the output
tracks the slower supply minus the dropout voltage until it reaches the set output voltage. If EN is connected to
BIAS, the device soft-starts as programmed, provided that VIN is present before VBIAS. If VBIAS and VEN are
present before VIN is applied and the set soft-start time has expired, then VOUT tracks VIN. If the soft-start time
has not expired, the output tracks VIN until VOUT reaches the value set by the charging soft-start capacitor.
Figure 28 shows the use of an RC-delay circuit to hold off VEN until VBIAS has ramped. This technique can also
be used to drive EN from VIN. An external control signal can also be used to enable the device after VIN and
VBIAS are present.
NOTE
When VBIAS and VEN are present and VIN is not supplied, this device outputs approximately
50 μA of current from OUT. Although this condition does not cause any damage to the
device, the output current may charge up the OUT node if total resistance between OUT
and GND (including external feedback resistors) is greater than 10 kΩ.
Submit Documentation Feedback
Copyright © 2010–2013, Texas Instruments Incorporated
Product Folder Links: TPS74801-Q1
13
TPS74801-Q1
SLVSAI4B – OCTOBER 2010 – REVISED JULY 2013
www.ti.com
VIN
VOUT
OUT
IN
R1
CIN
BIAS TPS74801
COUT
FB
R2
R
VBIAS
EN
CBIAS
C
GND
SS
CSS
Figure 28. Soft-Start Delay Using an RC Circuit to Enable the Device
OUTPUT NOISE
The TPS74801-Q1 provides low output noise when a soft-start capacitor is used. When the device reaches the
end of the soft-start cycle, the soft-start capacitor serves as a filter for the internal reference. By using a 0.001-μF
soft-start capacitor, the output noise is reduced by half and is typically 30-μVRMS for a 1.2-V output (10 Hz to 100
kHz). Further increasing CSS has little effect on noise. Because most of the output noise is generated by the
internal reference, the noise is a function of the set output voltage. The RMS noise with a 0.001-μF soft-start
capacitor is given in Equation 3:
(
VN(mVRMS) = 25
mVRMS
V
)x V
OUT(V)
(3)
The low output noise of the TPS74801-Q1 makes it a good choice for powering transceivers, PLLs, or other
noise-sensitive circuitry.
ENABLE AND SHUTDOWN
The enable (EN) pin is active high and is compatible with standard digital signaling levels. VEN below 0.4 V turns
the regulator off, while VEN above 1.1 V turns the regulator on. Unlike many regulators, the enable circuitry has
hysteresis and deglitching for use with relatively slowly ramping analog signals. This configuration allows the
TPS74801-Q1 to be enabled by connecting the output of another supply to the EN pin. The enable circuitry
typically has 50 mV of hysteresis and a deglitch circuit to help avoid on-off cycling as a result of small glitches in
the VEN signal.
The enable threshold is typically 0.8 V and varies with temperature and process variations. Temperature
variation is approximately –1 mV/°C; process variation accounts for most of the rest of the variation to the 0.4-V
and 1.1-V limits. If precise turn-on timing is required, a fast rise-time signal must be used to enable the
TPS74801-Q1.
If not used, EN can be connected to either IN or BIAS. If EN is connected to IN, it should be connected as close
as possible to the largest capacitance on the input to prevent voltage droops on that line from triggering the
enable circuit.
POWER GOOD
The power good (PG) pin is an open-drain output and can be connected to any 5.5-V or lower rail through an
external pull-up resistor. This pin requires at least 1.1 V on VBIAS in order to have a valid output. The PG output is
high-impedance when VOUT is greater than VIT + VHYS. If VOUT drops below VIT or if VBIAS drops below 1.9 V, the
open-drain output turns on and pulls the PG output low. The PG pin also asserts when the device is disabled.
The recommended operating condition of PG pin sink current is up to 1 mA, so the pull-up resistor for PG should
be in the range of 10 kΩ to 1 MΩ. If output voltage monitoring is not needed, the PG pin can be left floating.
INTERNAL CURRENT LIMIT
The TPS74801-Q1 features a factory-trimmed, accurate current limit that is flat over temperature and supply
voltage. The current limit allows the device to supply surges of up to 2 A and maintain regulation. The current
limit responds in approximately 10 μs to reduce the current during a short-circuit fault.
14
Submit Documentation Feedback
Copyright © 2010–2013, Texas Instruments Incorporated
Product Folder Links: TPS74801-Q1
TPS74801-Q1
www.ti.com
SLVSAI4B – OCTOBER 2010 – REVISED JULY 2013
The internal current limit protection circuitry of the TPS74801-Q1 is designed to protect against overload
conditions. It is not intended to allow operation above the rated current of the device. Continuously running the
TPS74801-Q1 above the rated current degrades device reliability.
THERMAL PROTECTION
Thermal protection disables the output when the junction temperature rises to approximately 160°C, allowing the
device to cool. When the junction temperature cools to approximately 140°C, the output circuitry is enabled.
Depending on power dissipation, thermal resistance, and ambient temperature the thermal protection circuit may
cycle on and off. This cycling limits the dissipation of the regulator, protecting it from damage as a result of
overheating.
Activation of the thermal protection circuit indicates excessive power dissipation or inadequate heatsinking. For
reliable operation, junction temperature should be limited to 150°C maximum. To estimate the margin of safety in
a complete design (including heatsink), increase the ambient temperature until thermal protection is triggered;
use worst-case loads and signal conditions. For good reliability, thermal protection should trigger at least 40°C
above the maximum expected ambient condition of the application. This condition produces a worst-case junction
temperature of 150°C at the highest expected ambient temperature and worst-case load.
The internal protection circuitry of the TPS74801-Q1 is designed to protect against overload conditions. It is not
intended to replace proper heatsinking. Continuously running the TPS74801-Q1 into thermal shutdown degrades
device reliability.
LAYOUT RECOMMENDATIONS AND POWER DISSIPATION
An optimal layout can greatly improve transient performance, PSRR, and noise. To minimize the voltage drop on
the input of the device during load transients, the capacitance on IN and BIAS should be connected as close as
possible to the device. This capacitance also minimizes the effects of parasitic inductance and resistance of the
input source and can, therefore, improve stability. To achieve optimal transient performance and accuracy, the
top side of R1 in Figure 25 should be connected as close as possible to the load. If BIAS is connected to IN, it is
recommended to connect BIAS as close to the sense point of the input supply as possible. This connection
minimizes the voltage drop on BIAS during transient conditions and can improve the turn-on response.
Knowing the device power dissipation and proper sizing of the thermal plane that is connected to the thermal pad
is critical to avoiding thermal shutdown and ensuring reliable operation. Power dissipation of the device depends
on input voltage and load conditions and can be calculated using Equation 4:
PD = (VIN - VOUT) ´ IOUT
(4)
Power dissipation can be minimized and greater efficiency can be achieved by using the lowest possible input
voltage necessary to achieve the required output voltage regulation.
The primary conduction path for heat is through the exposed pad to the printed circuit board (PCB). The pad can
be connected to ground or be left floating; however, it should be attached to an appropriate amount of copper
PCB area to ensure the device does not overheat. The maximum junction-to-ambient thermal resistance
depends on the maximum ambient temperature, maximum device junction temperature, and power dissipation of
the device and can be calculated using Equation 5:
(150°C - TA)
RθJA =
PD
(5)
Knowing the maximum RθJA, the minimum amount of PCB copper area needed for appropriate heatsinking can
be estimated using Figure 29.
Submit Documentation Feedback
Copyright © 2010–2013, Texas Instruments Incorporated
Product Folder Links: TPS74801-Q1
15
TPS74801-Q1
SLVSAI4B – OCTOBER 2010 – REVISED JULY 2013
www.ti.com
140
120
qJA (°C/W)
100
80
60
40
20
0
0
Note:
1
2
4
5
7
3
6
Board Copper Area (in2)
8
9
10
θJA value at board size of 9 in2 (that is, 3-in × 3-in) is a JEDEC standard.
Figure 29. θJA vs Board Size
Figure 29 shows the variation of θJA as a function of ground plane copper area in the board. It is intended only as
a guideline to demonstrate the effects of heat spreading in the ground plane and should not be used to estimate
actual thermal performance in real application environments.
NOTE
When the device is mounted on an application PCB, it is strongly recommended to use
ΨJT and ΨJB, as explained in the Estimating Junction Temperature section.
ESTIMATING JUNCTION TEMPERATURE
Using the thermal metrics ΨJT and ΨJB, as shown in the Thermal Information table, the junction temperature can
be estimated with corresponding formulas (given in Equation 6). For backwards compatibility, an older θJC,Top
parameter is listed as well.
YJT: TJ = TT + YJT · PD
YJB: TJ = TB + YJB · PD
(6)
Where PD is the power dissipation shown by Equation 4, TT is the temperature at the center-top of the IC
package, and TB is the PCB temperature measured 1mm away from the IC package on the PCB surface (see
Figure 31).
NOTE
Both TT and TB can be measured on actual application boards using a thermo-gun (an
infrared thermometer).
For more information about measuring TT and TB, see the application note SBVA025, Using New Thermal
Metrics, available for download at www.ti.com.
By looking at Figure 30, the new thermal metrics (ΨJT and ΨJB) have very little dependency on board size. That
is, using ΨJT or ΨJB with Equation 6 is a good way to estimate TJ by simply measuring TT or TB, regardless of the
application board size.
16
Submit Documentation Feedback
Copyright © 2010–2013, Texas Instruments Incorporated
Product Folder Links: TPS74801-Q1
TPS74801-Q1
www.ti.com
SLVSAI4B – OCTOBER 2010 – REVISED JULY 2013
12
YJT and YJB (°C/W)
10
YJB
8
DRC
RGW
6
4
2
YJT
0
0
1
2
3
4
5
6
7
8
9
10
Board Copper Area (in2)
Figure 30. ΨJT and ΨJB vs Board Size
For a more detailed discussion of why TI does not recommend using θJC(top) to determine thermal characteristics,
refer to application report SBVA025, Using New Thermal Metrics, available for download at www.ti.com. For
further information, refer to application report SPRA953, IC Package Thermal Metrics, also available on the TI
website.
TT on top
of IC
TB on PCB
surface
TB on PCB
TT on top of IC
1mm
1mm
(a) Example DRC (SON) Package Measurement
(b) Example RGW (QFN) Package Measurement
(1)
TT is measured at the center of both the X- and Y-dimensional axes.
(2)
TB is measured below the package lead on the PCB surface.
Figure 31. Measuring Points for TT and TB
Submit Documentation Feedback
Copyright © 2010–2013, Texas Instruments Incorporated
Product Folder Links: TPS74801-Q1
17
TPS74801-Q1
SLVSAI4B – OCTOBER 2010 – REVISED JULY 2013
www.ti.com
REVISION HISTORY
Changes from Revision A (February 2011) to Revision B
Page
•
Added AEC-Q100 info to Features. ...................................................................................................................................... 1
•
Added an extra sentence to the Description. ........................................................................................................................ 1
•
Removed Ordering Information table. ................................................................................................................................... 2
•
Changed Abs Max condition statement. ............................................................................................................................... 2
•
Changed TJ max temp limit from 125 to 150. ....................................................................................................................... 2
•
Added ESD ratings to Abs Max table. .................................................................................................................................. 2
•
Added RGW package to Thermal Information table. ............................................................................................................ 3
•
Added TA –40°C to 125°C in Electrical Characteristics condition; changed TJ to TA. .......................................................... 4
•
Changed TJ to TA in VREF test condition. ............................................................................................................................ 4
•
Removed TA and TJ from Electrical Characteristics table. .................................................................................................... 4
•
Added second package to Device Information section (Pinout drawing and Pin Descriptions table). ................................. 6
•
Changed TJ to TA throughout entire Typical Characteristics section. ................................................................................... 7
•
Image update - changed Junction Temperature to Ambient Temperature. .......................................................................... 9
•
Changed 125°C to 150°C in Thermal Protection section. .................................................................................................. 15
•
Image update - changed temperature from 125°C to 150°C in equation. .......................................................................... 15
•
Replaced ΨJT and ΨJB vs Board Size with 2-package image. ........................................................................................... 17
•
Replaced Measuring Points for TT and TB with 2-package image. ..................................................................................... 17
18
Submit Documentation Feedback
Copyright © 2010–2013, Texas Instruments Incorporated
Product Folder Links: TPS74801-Q1
PACKAGE OPTION ADDENDUM
www.ti.com
6-Feb-2020
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
Lead/Ball Finish
MSL Peak Temp
(2)
(6)
(3)
Op Temp (°C)
Device Marking
(4/5)
TPS74801QRGWRQ1
ACTIVE
VQFN
RGW
20
3000
Green (RoHS
& no Sb/Br)
NIPDAU
Level-3-260C-168 HR
-40 to 125
TPS
74801Q
TPS74801TDRCRQ1
ACTIVE
VSON
DRC
10
3000
Green (RoHS
& no Sb/Br)
NIPDAU
Level-3-260C-168 HR
-40 to 105
QVK
(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)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of
工商网监
湘ICP备2023018690号
