ISL6414IR-TK Intersil, ISL6414IR-TK Datasheet - Page 9

• Manufacturer Part Number: ISL6414IR-TK
• Description: TRIPLE OUTPUT LOW DROPOUT LINEAR REG. WITH FAULT PIN MODIFIC
• Manufacturer: Intersil

Specifications of ISL6414IR-TK

• Rohs Compliant: NO

Pin Descriptions
OUT1 - This pin is the output for LDO1. Bypass with a
minimum of 2.2µF, low ESR capacitor to GND for stable
operation.
V
Bypass with 2.2µF capacitor to GND. Both V
tied together on the PC board, close to the IC.
GND - Ground pin for LDO1 and LDO2.
CC1 - Compensation Capacitor for LDO1. Connect a
0.033µF capacitor from CC1 to GND.
SHDN - Shutdown input for LDO1 and LDO2. Connect to IN
for normal operation. Drive SHDN pin LOW to turn off LDO1
and LDO2.
OUT2 - This pin is the output for LDO2. Bypass with a
minimum of 2.2µF, low ESR capacitor to GND for stable
operation.
CT - Timing pin for the RESET circuit pulse width.
CC2 - Compensation capacitor for LDO2. Connect a
0.033µF capacitor from CC2 to GND.
OUT3 - This pin is output for LDO3. Bypass with a minimum
of 2.2µF, low ESR capacitor to GND3 for stable operation.
GND3 - Ground pin for LDO3.
CC3 - Compensation capacitor for LDO3. Connect a
0.033µF capacitor from CC3 to GND3.
SHDN3 - Shutdown input for LDO3. Connect to V
normal operation. Drive SHDN3 pin LOW to turn off LDO3.
FAULT - This is the power good indicator for LDO1. When
the 1.8V output is out of regulation (>±5%, typ.), this pin
goes LOW. This pin also goes LOW during thermal
shutdown and any overcurrent event on LDO1. Connect this
pin to GND, if unused. This pin remains HIGH in the
shutdown mode, as controlled by the SHDN pin (refer to
Figure 19).
RESET - This pin is the active-LOW output of the push-pull
output stage of the integrated reset supervisory circuit. The
reset circuit monitors V
pin, if V
output remains LOW, while the V
reset threshold, and for at least 25ms, after V
the RESET threshold.
RESET - This pin is the active-HIGH output of the push-pull
output stage of the integrated reset supervisory circuit. The
reset circuit monitors V
pin, if V
output remains HIGH, while the V
RESET threshold, and for at least 25ms, after V
above the RESET threshold.
IN
- Supply input pins. Connect to input power source.
IN
IN
falls below the RESET threshold. The RESET
falls below the RESET threshold. The RESET
IN
IN
and asserts a RESET output at this
and asserts a RESET output at this
9
IN
IN
pin voltage is below the
pin voltage is below the
IN
IN
pins must be
IN
rises above
IN
rises
for
ISL6414
Functional Description
The ISL6414 is a 3-in-1 multi-output, low dropout, regulator
designed for wireless chipset power applications. It supplies
three fixed output voltages 1.8V, 2.84V and 2.84V. The 1.8V
output from LDO1 remains active down to a V
(min.), ensuring proper BBP/MAC operation. Each LDO
consists of a 1.2V reference, error amplifier, MOSFET driver,
P-Channel pass transistor, dual-mode comparator and
internal feedback voltage divider.
The 1.2V band gap reference is connected to the error
amplifier’s inverting input. The error amplifier compares this
reference to the selected feedback voltage and amplifies the
difference. The MOSFET driver reads the error signal and
applies the appropriate drive to the P-Channel pass
transistor. If the feedback voltage is lower then the reference
voltage, the pass transistor gate is pulled lower, allowing
more current to pass and increasing the output voltage. If the
feedback voltage is higher then the reference voltage, the
pass transistor gate is driven higher, allowing less current to
pass to the output. The output voltage is fed back through an
internal resistor divider connected to OUT1/2/3 pins.
Additional blocks include an output overcurrent protection,
reverse battery protection, thermal sensor, fault detector,
RESET function and shutdown logic.
Internal P-Channel Pass Transistors
The ISL6414 features a typical 0.5Ω r
MOSFET pass transistors. This provides several advantages
over similar designs using PNP bipolar pass transistors. The
P-Channel MOSFET requires no base drive, which reduces
quiescent current considerably. PNP based regulators waste
considerable current in dropout when the pass transistor
saturates. They also use high base drive currents under
large loads. The ISL6414 does not suffer from these
problems.
Integrated RESET for MAC/ Baseband Processors
The ISL6414 includes a microprocessor supervisory block.
This block eliminates the extra RESET IC and external
components needed in wireless chipset applications. This
block performs a single function; it asserts a RESET signal
whenever the V
threshold, keeping it asserted for a programmable time (set
by external capacitor CT) after the V
above the RESET threshold.
The push pull output stage of the reset circuit provides both
an active-Low and an active-HIGH output. This function is
guaranteed to be in the correct state for V
reset comparator is designed to ignore transients on the V
pin. The RESET threshold for ISL6414 is 2.63V typical.
In addition to issuing a reset to the microprocessor during
power-up, power down and brownout conditions, this block
is relatively immune to short duration, negative-going V
transients/glitches.
IN
supply voltage decreases below a preset
IN
DS(ON)
pin voltage has risen
IN
down to 1V. The
P-channel
IN
= 2.7V
IN
IN