The MCP1603 is a high efficient, fully integrated
500 mA synchronous buck regulator whose 2.7V to
5.5V input voltage range makes it ideally suited for
applications powered from 1-cell Li-Ion or 2-cell/3-cell
NiMH/NiCd batteries.
At heavy loads, the MCP1603 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 MCP1603
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 MCP1603 to achieve the highest efficiency
over the entire operating current range.
The MCP1603 is 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. When a
fixed option is used, only three additional small external
components are needed to form a complete solution.
Couple this with the low profile, small-foot print
packages and the entire system solution is achieved
with minimal size.
Additional protection features include: UVLO,
overtemperature, and overcurrent protection.
† 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.
2: Reference Feedback Voltage Tolerance applies to adjustable output voltage setting.
is the output voltage setting.
3: V
R
4: 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
allowable power dissipation causes the device to initiate thermal shutdown.
5: The internal MOSFET switches have an integral diode from the L
to the GND pin. In cases where these diodes are forward-biased, the package power dissipation limits
must be adhered to. Thermal protection is not able to limit the junction temperature for these cases.
6: The current limit threshold is a cycle-by-cycle peak current limit.
= 100 mA, TA = +25°C. Boldface specifications apply over the TA range of -40°C to +85°C.
OUT
ParametersSymMinTypMaxUnitsConditions
Output Characteristics
Adjustable Output Voltage RangeV
Reference Feedback VoltageV
Reference Feedback Voltage
To le r an c e
Feedback Input Bias CurrentI
Output Voltage Tolerance FixedV
V
Line RegulationV
Load RegulationV
Internal Oscillator FrequencyF
Start Up TimeT
R
P-ChannelR
DSon
R
N-ChannelR
DSon
L
Pin Leakage CurrentI
X
Positive Current Limit Threshold+I
Note 1: The minimum V
has to meet two conditions: VIN ≥ 2.7V and VIN ≥ V
IN
LX(MAX)
OUT
FB
VFB
OUT
OUT
LINE-
REG
LOADREG
OSC
SS
DSon-P
DSon-N
LX
0.8—4.5VNote 2
—0.8—V
-3.0—+3.0%TA = -40°C to +25°C
-2.5—+2.5%T
—0.1—nA
-3.0%V
-2.5V
R
R
—0.3—%/VV
—0.35—%VIN=VR+1.5V,
1.52.02.8MHz
—0.6—msT
—500—mΩIP=100mA
—500—mΩIN= 100 mA
-1.0±0.11.0µASHDN =0V, VIN=5.5V,
—860—mANote 6
2: Reference Feedback Voltage Tolerance applies to adjustable output voltage setting.
3: V
is the output voltage setting.
R
4: 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
allowable power dissipation causes the device to initiate thermal shutdown.
5: The internal MOSFET switches have an integral diode from the L
to the GND pin. In cases where these diodes are forward-biased, the package power dissipation limits
must be adhered to. Thermal protection is not able to limit the junction temperature for these cases.
6: The current limit threshold is a cycle-by-cycle peak current limit.
Note:The graphs and tables provided following this note are a statistical summary based on a limited number of
samples and are provided for informational purposes only. The performance characteristics listed herein are
not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified
operating range (e.g., outside specified power supply range) and therefore outside the warranted range.
Note: Unless otherwise indicated, VIN= SHDN =3.6V, C
T
= +25°C. Adjustable or fixed output voltage options can be used to generate the Typical Performance Characteristics.