TPSM84424
www.ti.com.cn
ZHCSHN0A –FEBRUARY 2018–REVISED APRIL 2018
Electrical Characteristics (continued)
Over –40°C to +105°C ambient temperature, VIN = 12 V, VOUT = 1.2 V, IOUT = IOUTmax, fsw = 450 kHz (unless otherwise
noted); CIN1 = 2× 10-µF, 25-V, 1210 ceramic; CIN2 = 100-µF, 50-V, electrolytic; COUT = 4× 47-µF, 10-V, 1210 ceramic.
Minimum and maximum limits are specified through production test or by design. Typical values represent the most likely
parametric norm and are provided for reference only.
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX UNIT
SOFT START
tSS
Internal soft start time
1.25
5
ms
µA
ISS
Soft start charge current
THERMAL
Shutdown temperature
170
15
°C
°C
TSHDN
Thermal shutdown
Hysteresis
ENABLE (EN)
VEN-H
EN rising threshold
1.2
1.15
1.2
1.26
V
V
VEN-HYS
EN falling threshold
1.1
VEN = 1.1 V
VEN = 1.3 V
µA
µA
IEN
EN pin sourcing current
3.6
POWER GOOD (PGOOD)
VOUT rising (fault)
VOUT falling (good)
108%
106%
91%
89%
0.7
VPGOOD
PGOOD thresholds
VOUT rising (good)
VOUT falling (fault)
Minimum VIN for valid PGOOD VPGOOD < 0.5 V, IPGOOD = 2 mA
1
V
V
PGOOD low voltage
CAPACITANCE
2-mA pullup, VEN = 0 V
0.3
Ceramic type
20(3)
µF
µF
µF
CIN
External input capacitance
External output capacitance
Non-ceramic type
100(3)
COUT
min(4)
1500(5)
(3) A minimum of 20-µF ceramic input capacitance is required for proper operation. An additional 100 µF of bulk capacitance is
recommended for applications with transient load requirements. See the Input Capacitor section for further guidance.
(4) The minimum amount of required output capacitance varies depending on the output voltage (see Standard Component Values Table).
A minimum amount of ceramic output capacitance is required. Locate the capacitance close to the device. Adding additional ceramic or
non-ceramic capacitance close to the load improves the response of the regulator to load transients.
(5) The maximum output capacitance can be made up of all ceramic type or a combination of ceramic and a single non-ceramic type. See
the Low-ESR Output Capacitors Section for requirements of non-ceramic output capacitors.
6.6 Switching Characteristics
Over operating ambient temperature range (unless otherwise noted)
Minimum and maximum limits are specified through production test or by design. Typical values represent the most likely
parametric norm, and are provided for reference only.
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
SW
tON_MIN
tOFF_MIN
Minimum on-time
Minimum off-time
140
100
ns
ns
FREQUENCY (RT) and SYNCHRONIZATION (EN/SYNC)
Default switching frequency
RT pin = 110 kΩ
400
200
2
450
500
kHz
kHz
V
fSW
Switching frequency range
1600
VCLK-H
VCLK-L
Logic high input voltage
Logic low input voltage
Minimum CLK pulse width
0.8
V
TCLK-MIN
35
ns
Copyright © 2018, Texas Instruments Incorporated
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