MCP1602
2.0 MHz, 500 mA Synchronous Buck Regulator
with Power-Good
Features
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Over 90% Typical Efficiency
Output Current: Up To 500 mA
Power-Good Output with 262 ms Delay
Low Quiescent Current: 45 µA (typical)
Low Shutdown Current: 0.05 µA (typical)
Automatic PWM to PFM Mode Transition
Adjustable Output Voltage:
- 0.8V to 4.5V
Fixed Output Voltage:
- 1.2V, 1.5V, 1.8V, 2.5V, and 3.3V
2.0 MHz Fixed-Frequency PWM (Heavy Load)
Internally Compensated
Undervoltage Lockout (UVLO)
Overtemperture Protection
Overcurrent Protection
Space Saving Packages:
- 8-Lead MSOP
- 8-Lead 3x3 DFN
General Description
The MCP1602 is a high efficient, fully integrated
500 mA synchronous buck regulator with a power-
good monitor. The 2.7V to 5.5V input voltage range and
low quiescent current (45 µA, typical) makes the
MCP1602 ideally suited for applications powered from
1-cell Li-Ion or 2-cell/3-cell NiMH/NiCd batteries.
At heavy loads, the MCP1602 operates in the 2.0 MHz
fixed frequency PWM mode which provides a low
noise, low output ripple, small-size solution. When the
load is reduced to light levels, the MCP1602
automatically changes operation to a PFM mode to
minimize quiescent current draw from the battery. No
intervention is necessary for a smooth transition from
one mode to another. These two modes of operation
allow the MCP1602 to achieve the highest efficiency
over the entire operating current range.
The open-drain power-good feature of the MCP1602
monitors the output voltage and provides indication
when the output voltage is within 94% (typical) of the
regulation value. The typical 2% hystereses in the
power-good transition threshold as well as a
262 ms (typical) delay time ensures accurate power-
good signaling.
The MCP1602 is available in either the 8-pin DFN or
MSOP package. It is also available with either an
adjustable or fixed output voltage. The available fixed
output voltage options are 1.2V, 1.5V, 1.8V, 2.5V, and
3.3V.
Additional protection features include:
overtemperature, and overcurrent protection.
UVLO,
Applications
•
•
•
•
•
•
•
Cellular Telephones
Portable Computers
Organizers / PDAs
USB Powered Devices
Digital Cameras
Portable Equipment
+5V or +3.3V Distributed Systems
Package Types
MSOP-8
1 SHDN
2 V
CC
3 PG
P
GND
8
L
X
7
V
IN
6
SHDN
V
CC
PG
A
GND
1
2
3
4
3x3 DFN-8
8 P
GND
7 L
X
6 V
IN
5 V
OUT
/V
FB
4 A
GND
V
OUT
/V
FB
5
©
2007 Microchip Technology Inc.
DS22061A-page 1
MCP1602
Typical Application Circuit
4.7 µH
V
IN
2.7V to 4.5V
4.7 µF
6
V
IN
L
X
7
V
FB
5
P
GND
8
PG
3
R
PULLUP
10Ω
2
V
CC
4
V
OUT
1.5V @ 500 mA
4.7 µF
0.1 µF
A
GND
SHDN
1
MCP1602
ON
OFF
Processor
Reset
V
IN
DS22061A-page 2
©
2007 Microchip Technology Inc.
MCP1602
Functional Block Diagram
V
CC
Band
Gap
Thermal
Shutdown
TSD
IPEAK
PWM
I
PK
Limit
V
REF
V
IN
UVLO
UVLO
Soft Start
SHDN
ILIM
PWM
ILIM
PFM
Disable
Switcher
Slope
Comp
OSC
IPEAK
PFM
-ILPK
S
R
Q
Q
POFF
NOFF
L
X
Switch Drive
Logic and Timing
PWM/PFM
PFM Error Amp
PWM/PFM
Logic
P
GND
V
REF
PWM Error Amp
EA
IPEAK
PFM
IPEAK
PWM
-ILPK
-I
PK
Limit
V
REF
V
REF
V
CC
PG
OV Threshold
PG Generator
with Delay
V
FB
/ V
OUT
A
GND
UV Threshold
V
OUT
©
2007 Microchip Technology Inc.
DS22061A-page 3
MCP1602
1.0
ELECTRICAL
CHARACTERISTICS
†
Notice:
Stresses above those listed under "Maximum
Ratings" may cause permanent damage to the device. This is
a stress rating only and functional operation of the device at
those or any other conditions above those indicated in the
operational sections of this specification is not intended.
Exposure to maximum rating conditions for extended periods
may affect device reliability.
Absolute Maximum Ratings †
V
IN
- A
GND
......................................................................+6.0V
All Other I/O .............................. (A
GND
- 0.3V) to (V
IN
+ 0.3V)
LX to P
GND
............................................. -0.3V to (V
IN
+ 0.3V)
Output Short Circuit Current..................................Continuous
Power Dissipation (Note 6) ..........................Internally Limited
Storage Temperature.................................... -65
o
C to +150
o
C
Ambient Temp. with Power Applied................ -40
o
C to +85
o
C
Operating Junction Temperature.................. -40
o
C to +125
o
C
ESD Protection On All Pins:
HBM..............................................................................3 kV
MM...............................................................................200V
DC CHARACTERISTICS
Electrical Characteristics:
Unless otherwise indicated, V
IN
= 3.6V, C
OUT
= C
IN
= 4.7 µF, L = 4.7 µH,
V
OUT
(ADJ) = 1.8V, I
OUT
= 100 mA, T
A
= +25°C.
Boldface
specifications apply for the T
A
range of
-40
o
C to +85
o
C.
Parameters
Input Characteristics
Input Voltage
Maximum Output Current
Shutdown Current
Quiescent Current
SHDN, Logic Input Voltage Low
SHDN, Logic Input Voltage High
SHDN, Input Leakage Current
Undervoltage Lockout
Undervoltage Lockout Hystere-
sis
Thermal Shutdown
Thermal Shutdown Hysteresis
Output Characteristics
Adjustable Output Voltage
Range
Reference Feedback Voltage
Feedback Input Bias Current
Note 1:
2:
3:
4:
V
OUT
V
FB
I
VFB
0.8
—
—
—
0.8
-1.5
4.5
—
—
V
V
nA
Note 2
V
IN
I
OUT
I
IN_SHDN
I
Q
V
IL
V
IH
V
L_SHND
UVLO
UVLO
HYS
T
SHD
T
SHD-HYS
2.7
500
—
—
—
45
-1.0
2.40
—
—
—
—
—
0.05
45
—
—
±0.1
2.55
200
150
10
5.5
—
1
60
15
—
1.0
2.70
—
—
—
V
mA
µA
µA
%V
IN
%V
IN
µA
V
mV
°C
°C
Note 5, Note 6
Note 5, Note 6
Note 1
Note 1
SHDN = GND
SHDN = V
IN
, I
OUT
= 0 mA
V
IN
= 2.7V to 5.5V
V
IN
= 2.7V to 5.5V
V
IN
= 2.7V to 5.5V, SHDN = A
GND
V
IN
Falling
Sym
Min
Typ
Max
Units
Conditions
Shutdown/UVLO/Thermal Shutdown Characteristics
5:
6:
7:
The minimum V
IN
has to meet two conditions: V
IN
≥
2.7V and V
IN
≥
V
OUT
+ 0.5V.
Reference Feedback Voltage Tolerance applies to adjustable output voltage setting.
V
R
is the output voltage setting.
Regulation is measured at a constant junction temperature using low duty cycle pulse testing. Load
regulation is tested over a load range of 0.1 mA to the maximum specified output current. Changes in
output voltage due to heating effects are covered by the thermal regulation specification.
The maximum allowable power dissipation is a function of ambient temperature, the maximum allowable
temperature and the thermal resistance from junction to air (i.e. T
A
, T
J
,
θ
JA
). Exceeding the maximum
allowable power dissipation causes the device to initiate thermal shutdown.
The internal MOSFET switches have an integral diode from the L
X
pin to the V
IN
pin, and from the L
X
pin
to the GND pin. In cases where these diodes are forward-biased, the package power dissipation limits
must be adhered too. Thermal protection is not able to limit the junction temperature for these cases.
The current limit threshold is a cycle-by-cycle current limit.
DS22061A-page 4
©
2007 Microchip Technology Inc.
MCP1602
DC CHARACTERISTICS (CONTINUED)
Electrical Characteristics:
Unless otherwise indicated, V
IN
= 3.6V, C
OUT
= C
IN
= 4.7 µF, L = 4.7 µH,
V
OUT
(ADJ) = 1.8V, I
OUT
= 100 mA, T
A
= +25°C.
Boldface
specifications apply for the T
A
range of
-40
o
C to +85
o
C.
Parameters
Output Voltage Tolerance Fixed
Line Regulation
Load Regulation
Internal Oscillator Frequency
Start Up Time
R
DSon
P-Channel
R
DSon
N-Channel
L
X
Pin Leakage Current
Sym
V
OUT
V
LINE-
REG
Min
-2.5
—
—
1.6
—
—
—
-1.0
—
1.0
1.2
—
89
—
—
—
140
—
Typ
V
R
0.3
0.4
2.0
0.5
450
450
±0.01
700
—
Max
+2.5
—
—
2.4
—
—
—
1.0
—
5.5
5.5
96
—
—
—
—
560
0.2
Units
%
%/V
%
MHz
ms
mΩ
mΩ
µA
mA
V
Note 3
Conditions
V
IN
= V
R
+ 1V to 5.5V,
I
OUT
= 100 mA
V
IN
= V
R
+1.5V,
I
LOAD
= 100 mA to 500 mA,
Note 1
T
R
= 10% to 90%
I
P
= 100 mA
I
N
= 100 mA
SHDN = 0V, V
IN
= 5.5V, L
X
= 0V,
L
X
= 5.5V
Note 7
T
A
= 0°C to +70°C
T
A
= -40°C to +85°C
V
IN
≤
2.7V, I
SINK
= 100 µA
On Rising V
OUT
On Falling V
OUT
V
LOAD-
REG
F
OSC
T
SS
R
DSon-P
R
DSon-N
I
LX
Positive Current Limit Threshold +I
LX(MAX)
Power-Good (PG)
Voltage Range
V
PG
PG Threshold High
PG Threshold Low
PG Threshold Hysteresis
PG Threshold Tempco
PG Delay
PG Active Time-out Period
PG Output Voltage Low
V
TH_H
V
TH_L
V
TH_HYS
ΔV
TH
/ΔT
t
RPD
t
RPU
PG_V
OL
94
92
2
30
165
262
—
% of
V
OUT
% of
V
OUT
% of
V
OUT
ppm/°C
µs
ms
V
V
OUT
= (V
TH_H
+ 100 mV) to
(V
TH_L
- 100 mV)
V
OUT
= (V
TH_L
- 100 mV) to
(V
TH_H
+ 100 mV), I
SINK
= 1.2mA
V
OUT
= V
TH_L
- 100 mV,
I
PG
= 1.2 mA, V
IN
> 2.7V
I
PG
= 100 µA, 1.0 < V
IN
< 2.7V
Note 1:
2:
3:
4:
5:
6:
7:
The minimum V
IN
has to meet two conditions: V
IN
≥
2.7V and V
IN
≥
V
OUT
+ 0.5V.
Reference Feedback Voltage Tolerance applies to adjustable output voltage setting.
V
R
is the output voltage setting.
Regulation is measured at a constant junction temperature using low duty cycle pulse testing. Load
regulation is tested over a load range of 0.1 mA to the maximum specified output current. Changes in
output voltage due to heating effects are covered by the thermal regulation specification.
The maximum allowable power dissipation is a function of ambient temperature, the maximum allowable
temperature and the thermal resistance from junction to air (i.e. T
A
, T
J
,
θ
JA
). Exceeding the maximum
allowable power dissipation causes the device to initiate thermal shutdown.
The internal MOSFET switches have an integral diode from the L
X
pin to the V
IN
pin, and from the L
X
pin
to the GND pin. In cases where these diodes are forward-biased, the package power dissipation limits
must be adhered too. Thermal protection is not able to limit the junction temperature for these cases.
The current limit threshold is a cycle-by-cycle current limit.
©
2007 Microchip Technology Inc.
DS22061A-page 5
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