TPS22949_101 Datasheet, PDF (1/28 Pages) Texas Instruments – CURRENT-LIMITED LOAD SWITCH WITH LOW NOISE REGULATION CAPABILITY

TPS22949
TPS22949A
www.ti.com
SLVS908C – FEBRUARY 2009 – REVISED JANUARY 2010
CURRENT-LIMITED LOAD SWITCH WITH LOW NOISE REGULATION CAPABILITY
Check for Samples: TPS22949, TPS22949A
FEATURES
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• Integrated Current Limiter
– Input Voltage Range: 1.62 V to 4.5 V
– Low ON-Resistance
– r_ON = 300-mΩ at V_IN = 4.5 V
– r_ON = 350-mΩ at V_IN = 3.3 V
– r_ON = 400-mΩ at V_IN = 2.5 V
– r_ON = 600-mΩ at V_IN = 1.8 V
– Integrated 100-mA Minimum Current Limit
– Undervoltage Lockout
– Fast-Current Limit Response Time
– Integrated Fault Blanking and Auto Restart
• Stable Without Current Limiter Output
Capacitor (TPS22949A Only)
• Integrated Low-Noise RF LDO
– Input Voltage Range: 1.62 V to 4.5 V
– Low Noise: 50 μVrms (10 Hz to 100 kHz)
– 80-dB V_IN PSRR (10 Hz to 10 kHz)
– Fast Start-Up Time: 130 μs
– Low Dropout 100 mV at I_load =100 mA
– Integrated Output Discharge
– Stable With 2.2-μF Output Capacitor
• 1.8-V Compatible Control Input Threshold
• ESD Performance Tested Per JESD 22
– 3500-V Human-Body Model
(A114-B, Class II)
– 1000-V Charged-Device Model
(C101)
• Tiny 8-Terminal YZP Package (1.9 mm ×
0.9 mm, 0.5-mm Pitch, 0.5-mm Height) and
SON-8 (DRG) 3.0 mm × 3.0 mm
APPLICATIONS
• Fingerprint Module Protection
• Portable Consumer Electronics
• Smart Phone
• Notebooks
• Control Access Systems
DESCRIPTION
The TPS22949 and TPS22949A are devices that
provides protection to systems and loads in
high-current conditions. The device contains a
500-mΩ current-limited P-channel MOSFET that can
operate over an input voltage range of 1.62 V to
4.5 V as well as a low-dropout (LDO) regulator with a
fixed output voltage of 1.8 V.
The switch is controlled by an on/off input (EN1),
which is capable of interfacing directly with
low-voltage control signals. When the switch current
reaches
the
maximum
limit,
the
TPS22949/TPS22949A
operates
in
a
constant-current mode to prohibit excessive currents
from causing damage. If the constant current
condition still persists after 12 ms, these devices shut
off the switch and pull the fault signal pin (OC) low.
The TPS22949/TPS22949A has an auto-restart
feature that turns the switch on again after 70 ms if
the EN1 pin is still active.
The output of the current limiter is internally
connected to a RF low-dropout (LDO) regulator that
offers good ac performance with very low ground
current, good power-supply rejection ratio (PSRR),
low noise, fast start-up, and excellent line and load
transient response. The output of the regulator is
stable with ceramic capacitors. This LDO uses a
precision voltage reference and feedback loop to
achieve overall accuracy of 2% over all load, line,
process, and temperature variations.
The TPS22949A integrates additional internal
circuitry that increases the current limit of the switch
during the power-up sequence. This feature allows
the TPS22949A to operate without a storage
capacitor at the input of the LDO.
The TPS22949 and TPS22949A are available in a
space-saving 8-terminal WCSP (YZP) or in a 8-pin
SON package (DRG). Both are characterized for
operation over the free-air temperature range of
–40°C to 85°C.
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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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