MCP1826 MICROCHIP [Microchip Technology], MCP1826 Datasheet - Page 15

• Manufacturer Part Number: MCP1826
• Description: 1000 mA, Low Voltage, Low Quiescent Current LDO Regulator
• Manufacturer: MICROCHIP [Microchip Technology]

3.0
The descriptions of the pins are listed in
TABLE 3-1:
3.1
The SHDN input is used to turn the LDO output voltage
on and off. When the SHDN input is at a logic-high
level, the LDO output voltage is enabled. When the
SHDN input is pulled to a logic-low level, the LDO
output voltage is disabled. When the SHDN input is
pulled low, the PWRGD output also goes low and the
LDO enters a low quiescent current shutdown state
where the typical quiescent current is 0.1 µA.
3.2
Connect the unregulated or regulated input voltage
source to V
several inches away from the LDO, or the input source
is a battery, it is recommended that an input capacitor
be used. A typical input capacitance value of 1 µF to
10 µF should be sufficient for most applications.
3.3
Connect the GND pin of the LDO to a quiet circuit
ground. This will help the LDO power supply rejection
ratio and noise performance. The ground pin of the
LDO only conducts the quiescent current of the LDO
(typically 120 µA), so a heavy trace is not required.
For applications have switching or noisy inputs tie the
GND pin to the return of the output capacitor. Ground
planes help lower inductance and voltage spikes
caused by fast transient load currents and are
recommended for applications that are subjected to
fast load transients.
3.4
The V
LDO. A minimum output capacitance of 1.0 µF is
required for LDO stability. The MCP1826/MCP1826S is
stable with ceramic, tantalum and aluminum-electro-
lytic capacitors. See Section 4.3 “Output Capacitor”
for output capacitor selection guidance.
© 2007 Microchip Technology Inc.
Exposed Pad Exposed Pad Exposed Pad
3-Pin Fixed
Output
OUT
—
—
—
1
2
3
PIN DESCRIPTION
Shutdown Control Input (SHDN)
Input Voltage Supply (V
Ground (GND)
Regulated Output Voltage (V
pin is the regulated output voltage of the
IN
. If the input voltage source is located
5-Pin Fixed
PIN FUNCTION TABLE
Output
—
1
2
3
4
5
Adjustable
Output
—
1
2
3
4
5
IN
Table
)
OUT
3-1.
)
PWRGD
SHDN
Name
V
GND
ADJ
V
EP
OUT
IN
MCP1826/MCP1826S
3.5
The PWRGD output is an open-drain output used to
indicate when the LDO output voltage is within 92%
(typically) of its nominal regulation value. The PWRGD
threshold has a typical hysteresis value of 2%. The
PWRGD output is delayed by 200 µs (typical) from the
time the LDO output is within 92% + 3% (max hystere-
sis) of the regulated output value on power-up. This
delay time is internally fixed.
3.6
For adjustable applications, the output voltage is
connected to the ADJ input through a resistor divider
that sets the output voltage regulation value. This
provides the user the capability to set the output
voltage to any value they desire within the 0.8V to 5.0V
range of the device.
3.7
The DDPAK and TO-220 package have an exposed tab
on the package. A heat sink may may be mount to the
tab to aid in the removal of heat from the package
during operation. The exposed tab is at the ground
potential of the LDO.
Description
Shutdown Control Input (active-low)
Input Voltage Supply
Ground
Regulated Output Voltage
Power Good Output
Voltage Adjust/Sense Input
Exposed Pad of the Package (ground potential)
Power Good Output (PWRGD)
Output Voltage Adjust Input (ADJ)
Exposed Pad (EP)
DS22057A-page 15