MCP1825/MCP1825S
500 mA, Low Voltage, Low Quiescent Current LDO Regulator
Features
• 500 mA Output Current Capability
• Input Operating Voltage Range: 2.1V to 6.0V
• Adjustable Output Voltage Range: 0.8V to 5.0V
(MCP1825 only)
• Standard Fixed Output Voltages:
- 0.8V, 1.2V, 1.8V, 2.5V, 3.0V, 3.3V, 5.0V
• Other Fixed Output Voltage Options Available
Upon Request
• Low Dropout Voltage: 210 mV Typical at 500 mA
• Typical Output Voltage Tolerance: 0.5%
• Stable with 1.0 µF Ceramic Output Capacitor
• Fast response to Load Transients
• Low Supply Current: 120 µA (typical)
• Low Shutdown Supply Current: 0.1 µA (typical)
(MCP1825 only)
• Fixed Delay on Power Good Output
(MCP1825 only)
• Short Circuit Current Limiting and
Overtemperature Protection
• TO-263-5 (DDPAK-5), TO-220-5, SOT-223-5
Package Options (MCP1825).
• TO-263-3 (DDPAK-3), TO-220-3, SOT-223-3
Package Options (MCP1825S).
Description
The MCP1825/MCP1825S is a 500 mA Low Dropout
(LDO) linear regulator that provides high current and
low output voltages. The MCP1825 comes in a fixed or
adjustable output voltage version, with an output
voltage range of 0.8V to 5.0V. The 500 mA output
current capability, combined with the low output voltage
capability, make the MCP1825 a good choice for new
sub-1.8V output voltage LDO applications that have
high current demands. The MCP1825S is a 3-pin fixed
voltage version.
The MCP1825/MCP1825S is stable using ceramic
output capacitors that inherently provide lower output
noise and reduce the size and cost of the entire
regulator solution. Only 1 µF of output capacitance is
needed to stabilize the LDO.
Using CMOS construction, the quiescent current
consumed by the MCP1825/MCP1825S is typically
less than 120 µA over the entire input voltage range,
making it attractive for portable computing applications
that demand high output current. The MCP1825
versions have a Shutdown (SHDN) pin. When shut
down, the quiescent current is reduced to less than
0.1 µA.
On the MCP1825 fixed output versions, the scaled-
down output voltage is internally monitored and a
power good (PWRGD) output is provided when the
output is within 92% of regulation (typical). The
PWRGD delay is internally fixed at 110 µs (typical).
The overtemperature and short circuit current-limiting
provide additional protection for the LDO during system
fault conditions.
Applications
•
•
•
•
•
•
High-Speed Driver Chipset Power
Networking Backplane Cards
Notebook Computers
Network Interface Cards
Palmtop Computers
2.5V to 1.XV Regulators
©
2008 Microchip Technology Inc.
DS22056B-page 1
MCP1825/MCP1825S
Package Types
MCP1825
DDPAK-5
TO-220-5
Fixed/Adjustable
DDPAK-3
MCP1825S
TO-220-3
1
1 2 3 4 5
1 2 3 4 5
2
3
1
2
3
SOT-223-5
6
SOT-223-3
4
1
2
3
4
5
1
2
3
Pin
1
2
3
4
5
6
Fixed
SHDN
V
IN
GND (TAB)
V
OUT
PWRGD
GND (TAB)
Adjustable
SHDN
V
IN
GND (TAB)
V
OUT
ADJ
GND (TAB)
Pin
1
2
3
4
V
IN
GND (TAB)
V
OUT
GND (TAB)
DS22056B-page 2
©
2008 Microchip Technology Inc.
MCP1825/MCP1825S
Typical Applications
MCP1825 Fixed Output Voltage
PWRGD
On
Off
V
IN
= 2.3V to 2.8V
C
1
4.7 µF
SHDN
V
IN
1
GND
V
OUT
R
1
100 kΩ
V
OUT
= 1.8V @ 500 mA
C
2
1 µF
MCP1825 Adjustable Output Voltage
V
ADJ
R
2
20 kΩ
On
Off
V
IN
= 2.1V to 2.8V
C
1
4.7 µF
GND
SHDN
V
IN
1
V
OUT
R
1
40 kΩ
V
OUT
= 1.2V @ 500 mA
C
2
1 µF
©
2008 Microchip Technology Inc.
DS22056B-page 3
MCP1825/MCP1825S
Functional Block Diagram - Adjustable Output
PMOS
V
IN
V
OUT
Undervoltage
Lock Out
(UVLO)
I
SNS
C
f
R
f
ADJ/SENSE
SHDN
Driver w/limit
and SHDN
SHDN
V
REF
V IN
SHDN
Soft-Start
Comp
GND
92% of V
REF
T
DELAY
Reference
+
EA
–
Overtemperature
Sensing
DS22056B-page 4
©
2008 Microchip Technology Inc.
MCP1825/MCP1825S
Functional Block Diagram - Fixed Output (3-Pin)
PMOS
V
IN
V
OUT
Undervoltage
Lock Out
(UVLO)
Sense
I
SNS
C
f
R
f
SHDN
Driver w/limit
and SHDN
SHDN
V
REF
V IN
SHDN
Soft-Start
Comp
GND
92% of V
REF
T
DELAY
Reference
+
EA
–
Overtemperature
Sensing
©
2008 Microchip Technology Inc.
DS22056B-page 5
