MCP1603/B/L
2.0 MHz, 500 mA Synchronous Buck Regulator
Features
• Over 90% Typical Efficiency
• Output Current Up To 500 mA
• Low PFM Quiescent Current = 45 µA, typical
(MCP1603/L)
• Low Shutdown Current = 0.1 µA, typical
• Adjustable Output Voltage:
- 0.8V to 4.5V
• Fixed Output Voltage:
- 1.2V, 1.5V, 1.8V, 2.5V, 3.3V (MCP1603/L)
- 1.8V, 3.3V (MCP1603B)
• 2.0 MHz Fixed-Frequency PWM (Heavy Load)
• Automatic PWM-to-PFM Mode Transition
(MCP1603/L)
• PWM Mode Only Option (MCP1603B)
• 100% Duty Cycle Operation
• Internally Compensated
• Undervoltage Lockout (UVLO)
• Overtemperature Protection
• Space Saving Packages:
- 5-Lead TSOT, Two Pinout Types (MCP1603/L)
- 8-Lead 2 x 3 DFN
General Description
The MCP1603/B/L is a high-efficiency, 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/B/L operates in the
2.0 MHz fixed frequency pulse-width modulation
(PWM) mode, which provides a low noise, low-output
ripple, small-size solution. When the load is reduced to
light levels, the MCP1603/L automatically changes
operation to a Pulse Frequency Modulation (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/L to achieve the
highest efficiency over the entire operating current
range.
The MCP1603B device disables the PFM mode
switching, and operates only in normal PWM mode
over the entire load range (without skipping).
MCP1603B is for applications that cannot tolerate the
low-frequency output ripple associated with PFM
switching.
The MCP1603/B/L family is available with either an
adjustable or fixed-output voltage. The available fixed
output voltage options for MCP1603/L are 1.2V, 1.5V,
1.8V, 2.5V and 3.3V, and for MCP1603B are 1.8 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:
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
Headsets
2007-2012 Microchip Technology Inc.
DS22042B-page 1
MCP1603/B/L
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 specifica-
tion is not intended. Exposure to maximum rating con-
ditions for extended periods may affect device
reliability.
Absolute Maximum Ratings †
V
IN
- GND.......................................................................+6.0V
All Other I/O ............................... (GND - 0.3V) to (V
IN
+ 0.3V)
L
X
to GND .............................................. -0.3V to (V
IN
+ 0.3V)
Output Short Circuit Current ................................. Continuous
Power Dissipation
(Note
5)
.......................... Internally Limited
Storage Temperature ....................................-65°C to +150°C
Ambient Temp. with Power Applied ................-40°C to +85°C
Operating Junction Temperature...................-40°C to +125°C
ESD Protection On All Pins:
HBM ............................................................................. 4 kV
MM ..............................................................................300V
DC CHARACTERISTICS
Electrical Characteristics:
Unless otherwise indicated, MCP1603/L, V
IN
= SHDN = 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 over the T
A
range of -40°C
to +85°C.
Parameters
Input Characteristics
Input Voltage
Maximum Output Current
Shutdown Current
Quiescent Current - PFM
Quiescent Current - PWM
V
IN
I
OUT
I
IN_SHDN
I
Q
I
Q
2.7
500
—
—
1.0
—
—
0.1
45
2.7
5.5
—
1
60
4
V
mA
µA
µA
mA
Note 1
Note 1
SHDN = GND
SHDN = V
IN
, I
OUT
= 0 mA,
device switching
SHDN = V
IN
, I
OUT
= 0 mA,
device switching (MCP1603B)
Sym
Min
Typ
Max
Units
Conditions
Shutdown/UVLO/Thermal Shutdown Characteristics
SHDN, Logic Input Voltage Low
SHDN, Logic Input Voltage High
SHDN, Input Leakage Current
Undervoltage Lockout
Undervoltage Lockout Hysteresis
Thermal Shutdown
Thermal Shutdown Hysteresis
Note 1:
V
IL
V
IH
I
L_SHDN
UVLO
UVLO
HYS
T
SHD
T
SHD-HYS
—
45
-1.0
2.12
—
—
—
—
—
±0.1
2.28
140
150
10
15
—
1.0
2.43
—
—
—
%V
IN
V
IN
= 2.7V to 5.5V
%V
IN
V
IN
= 2.7V to 5.5V
µA
V
mV
°C
°C
Note 4, Note 5
Note 4, Note 5
V
IN
= 2.7V to 5.5V
V
IN
Falling
2:
3:
4:
5:
6:
The input voltage should be greater then the output voltage plus headroom voltage; higher load currents
increase the input voltage required for regulation. MCP1603B device requires a minimum load for
regulation. See
Section 2.0, Typical Performance Curves
for typical operating voltage ranges.
Reference Feedback Voltage Tolerance applies to adjustable output voltage setting.
V
R
is the output voltage setting.
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
,
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 to. Thermal protection is not able to limit the junction temperature for these cases.
The current limit threshold is a cycle-by-cycle peak current limit.
2007-2012 Microchip Technology Inc.
DS22042B-page 5
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