TPS22946_10 Datasheet, PDF (1/26 Pages) Texas Instruments – ULTRA-LOW POWER, LOW INPUT VOLTAGE, CURRENT-LIMITED LOAD SWITCH WITH SHUT-OFF, AUTO-RESTART, AND OVER-CURRENT CONDITION TIME-OUT

TPS22946
www.ti.com
SLVS984A – SEPTEMBER 2009 – REVISED FEBRUARY 2010
ULTRA-LOW POWER, LOW INPUT VOLTAGE, CURRENT-LIMITED LOAD SWITCH
WITH SHUT-OFF, AUTO-RESTART, AND OVER-CURRENT CONDITION TIME-OUT
Check for Samples: TPS22946
FEATURES
1
• Ultra-Low Quiescent Current 1 mA (typ)
at V_IN = 1.8 V
• Input Voltage Range: 1.62 V to 5.5 V
• Low ON-Resistance
– r_ON = 300 mΩ at V_IN = 5.5 V
– r_ON = 400 mΩ at V_IN = 3.3 V
– r_ON = 500 mΩ at V_IN = 2.5 V
– r_ON = 600 mΩ at V_IN = 1.8 V
• Selectable Minimum Current Limit:
155 mA, 70 mA, or 30 mA
• Integrated Inrush Current Timeout (8 ms)
• Shutdown Current: < 1 mA
• Thermal Shutdown
• Fault Blanking
• Auto Restart
• Over-Current Condition Timeout (Automatic
Disable for Permanent Over-Current)
• 1.8-V Compatible Control Input
• ESD Performance Tested Per JESD 22
– 6000-V Human-Body Model
(A114-B, Class II)
• Tiny WCSP Package 1.4mm x 0.9 mm (YZP)
APPLICATIONS
• Fingerprint Module Protection
• Portable Consumer Electronics
• Mobile Phones
• Smartphone
• Notebooks
• GPS Devices
DESCRIPTION
The TPS22946 is an ultra-low power load switch that
provides protection to systems and loads in
high-current conditions. The device contains a
300-mΩ current-limited P-channel MOSFET that can
operate over an input voltage range of 1.62 V to
5.5 V. The switch is controlled by an on/off input
(ON), which is capable of interfacing directly with
low-voltage control signals. The TPS22946 includes
thermal shutdown protection that prevents damage to
the device when a continuous over-current condition
causes excessive heating by turning off the switch.
When the switch current reaches the maximum limit,
the TPS22946 operates in a constant-current mode to
prohibit excessive currents from causing damage.
The current limit can be selected using the CL input:
a high CL input sets the current limit to 155 mA, a low
CL input sets the current limit to 70 mA, and a
floating CL input sets the current limit to 30 mA.
If the constant current condition still persists after 10
ms, the switch is turned off and the fault signal pin
(OC) is pulled low. The TPS22946 has an
auto-restart feature which turns the switch on again
after 70 ms if the ON pin is still active. If the
TPS22946 remains in an over-current condition for 5
seconds, the device shuts off until it is turned back on
by setting the ON control signal off and then on
again.
If the device is used to protect an LDO, the inrush
current required by the LDO at startup can, in some
cases, exceed the current limit and initiate a blanking
(current limiting) condition. TPS22946 provides
allowance for this scenario during startup of the LDO
by temporarily increasing the current limit to 435-mA
for 8-ms after the load switch is enabled.
The TPS22946 is available in space-saving
6-terminal WCSP (YZP) package. It is characterized
for operation over the free-air temperature range of
–40°C to 85°C.
TPS22946
r_ON (TYP) AT
5.5 V
300 mΩ
Table 1. FEATURE LIST
CURRENT LIMIT
30 mA, 70 mA, or 155 mA
INTEGRATED
INRUSH
CURRENT
TIMEOUT
Yes
CURRENT
LIMIT
BLANKING
TIME
10 ms
AUTO-
RESTART
TIME
70 ms
OVER-
CURRENT
TIMEOUT
6s
ENABLE
Active high
1
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.
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.
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