Datasheet

LMZ31503
SNVS992 –JULY 2013 www.ti.com
ELECTRICAL CHARACTERISTICS
Over -40°C to 85°C free-air temperature, PVIN = VIN = 12 V, V
OUT
= 1.8 V, I
OUT
= 3A,
C
IN1
= 2x 22 µF ceramic, C
IN2
= 68 µF poly-tantalum, C
OUT1
= 4x 47 µF ceramic (unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
I
OUT
Output current T
A
= 85°C, natural convection 0 3 A
VIN Input bias voltage range Over I
OUT
range 4.5 14.5 V
PVIN Input switching voltage range Over I
OUT
range 1.6
(1)
14.5 V
VIN = increasing 4.0 4.5
UVLO VIN Undervoltage lockout V
VIN = decreasing 3.5 3.85
V
OUT(adj)
Output voltage adjust range Over I
OUT
range 0.8 5.5 V
Set-point voltage tolerance T
A
= 25°C, I
OUT
= 0A ±1.0%
(2)
Temperature variation -40°C ≤ T
A
≤ +85°C, I
OUT
= 0A ±0.3%
V
OUT
Line regulation Over PVIN range, T
A
= 25°C, I
OUT
= 0A ±0.1%
Load regulation Over I
OUT
range, T
A
= 25°C ±0.1%
Total output voltage variation Includes set-point, line, load, and temperature variation ±1.5%
(2)
V
OUT
= 5V, f
SW
= 780kHz 91.5 %
V
OUT
= 3.3V, f
SW
= 630kHz 89.0 %
V
OUT
= 2.5V, f
SW
= 480kHz 86.9 %
PVIN = VIN = 12 V
I
O
= 1.5 A
V
OUT
= 1.8V, f
SW
= 480kHz 85.2 %
V
OUT
= 1.2V, f
SW
= 480kHz 82.1 %
η Efficiency V
OUT
= 0.8V, f
SW
= 330kHz 78.7 %
PVIN = VIN = 5 V V
OUT
= 3.3V, f
SW
= 630kHz 93.3 %
I
O
= 1.5 A
V
OUT
= 2.5V, f
SW
= 480kHz 91.4 %
V
OUT
= 1.8V, f
SW
= 480kHz 88.8 %
V
OUT
= 1.2V, f
SW
= 480kHz 85.2 %
V
OUT
= 0.8V, f
SW
= 330kHz 81.8 %
Output voltage ripple 20 MHz bandwith 35 mV
PP
I
LIM
Overcurrent threshold 5.8 A
Recovery time 190 µs
Transient response 1.0 A/µs load step from 50 to 100% I
OUT(max)
V
OUT
35 mV
over/undershoot
V
INH-H
Inhibit High Voltage 1.30 Open
(3)
Inhibit Control V
V
INH-L
Inhibit Low Voltage –0.3 1.05
INH Input current INH < 1.1 V -1.15 μA
INH Hysteresis current INH > 1.26 V -3.4 μA
I
I(stby)
Input standby current INH pin to AGND 2 4 µA
Good 94%
V
OUT
rising
Fault 109%
PWRGD Thresholds
Power
Fault 91%
Good
V
OUT
falling
Good 106%
PWRGD Low Voltage I(PWRGD) = 2 mA 0.3 V
f
SW
Switching frequency Over VIN and I
OUT
ranges, RT/CLK pin OPEN 270 330 390 kHz
f
CLK
Synchronization frequency 330 780 kHz
V
CLK-H
CLK High-Level Threshold 2.0 5.5 V
CLK Control
V
CLK-L
CLK Low-Level Threshold 0.8 V
D
CLK
CLK Duty cycle 20% 80%
Thermal shutdown 160 175 °C
Thermal Shutdown
Thermal shutdown hysteresis 10 °C
(1) The minimum PVIN voltage is 1.6V or (V
OUT
+ 0.7V) , whichever is greater. VIN must be greater than 4.5V.
(2) The stated limit of the set-point voltage tolerance includes the tolerance of both the internal voltage reference and the internal
adjustment resistor. The overall output voltage tolerance will be affected by the tolerance of the external R
SET
resistor.
(3) This control pin has an internal pullup. If this pin is left open circuit, the device operates when input power is applied. A small low-
leakage (<300 nA) MOSFET is recommended for control. See the application section for further guidance.
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