SI91842DT-285-E3 Vishay, SI91842DT-285-E3 Datasheet - Page 9

• Manufacturer Part Number: SI91842DT-285-E3
• Description: 150mA LDO REGULATOR WITH ERROR PIN
• Manufacturer: Vishay

Specifications of SI91842DT-285-E3

• Number Of Outputs: 1
• Polarity: Positive
• Input Voltage Max: 6 V
• Output Voltage: 2.85 V
• Output Type: Fixed
• Dropout Voltage (max): 0.08 V at 50 mA
• Output Current: 300 mA
• Line Regulation: 0.18 % / V
• Load Regulation: 25 mV
• Voltage Regulation Accuracy: 1.5 %
• Maximum Power Dissipation: 0.44 W
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: SOT-23
• Minimum Operating Temperature: - 40 C
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

DETAILED DESCRIPTION
The Si91842 is a low-noise, low drop-out and low quiescent
current linear voltage regulator, packaged in a small footprint
Thin SOT23-5 package. The Si91842 can supply loads up to
150 mA. As shown in the block diagram, the circuit consists of
a bandgap reference, error amplifier, p-channel pass transistor
and feedback resistor string. Additional blocks, not shown in
the block diagram, include a precise current limiter, reverse
battery and current protection, and thermal sensor.
Thermal Overload Protection
The thermal overload protection limits the total power
dissipation and protects the device from being damaged.
When the junction temperature exceeds 150_, the device
turns the p-channel pass transistor off.
Reverse Battery Protection
The Si91842 has a battery reverse protection circuitry that
disconnects the internal circuitry when V
GND voltage. There is no current drawn in such an event.
When the SD pin is hardwired to V
the SD pin to V
Vishay Siliconix maintains worldwide manufacturing capability. Products may be manufactured at one of several qualified locations. Reliability data for Silicon Technology and
Package Reliability represent a composite of all qualified locations.
http://www.vishay.com/ppg?71732.
Document Number: 71732
S-50956—Rev. F, 16-May-05
BLOCK DIAGRAM
IN
V
SD
IN
via a 100-kW resistor if reverse battery
Reverse Polarity
Protection
Reference
Shutdown
Control
IN
, the user must connect
Thermal
Current
Sensor
Limit
IN
drops below the
−
+
For related documents such as package/tape drawings, part marking, and reliability data, see
Si91842
protection is desired. Hardwiring the SD pin directly to the V
pin is allowed when reverse battery protection is not desired.
ERROR
ERROR is an open drain output that goes low when V
less than 4% of its normal value. To obtain a logic level output,
connect a pull-up resister from ERROR to V
voltage equal to or less than V
impedance (off) when SD pin is low.
Auto-Discharge/No-Discharge
V
when SD pin is low for the Si91842. the Si91844 does not have
a discharge path when the SD pin is low.
Stability
The circuit is stable with only a small output capacitor equal to
6 nF/mA (= 1 mF @ 150 mA). Since the bandwidth of the error
amplifier is around 1−3 MHz and the dominant pole is at the
output node, the capacitor should be capacitive in this range,
i.e., for 150-mA load current, an ESR <0.4 W is necessary.
Parasitic inductance of about 10 nH can be tolerated.
OUT
has an internal 100-W (typ.) discharge path to ground
GND
ERROR
V
OUT
Vishay Siliconix
IN
.
ERROR pin is high
OUT
Si91842
www.vishay.com
or any other
OUT
IN
is
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