MCP1602
2.0 MHz, 500 mA Synchronous Buck Regulator
with Power-Good
Features
General Description
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The MCP1602 is a high efficient, fully integrated
500 mA synchronous buck regulator with a powergood 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.
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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
Applications
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Cellular Telephones
Portable Computers
Organizers / PDAs
USB Powered Devices
Digital Cameras
Portable Equipment
+5V or +3.3V Distributed Systems
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 powergood 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,
Package Types
MSOP-8
3x3 DFN-8
PGND 8
SHDN
1
8 PGND
2 VCC
LX 7
VCC
2
7 LX
3 PG
VIN 6
PG
3
6 VIN
4 AGND VOUT/VFB 5
AGND
4
5 VOUT/VFB
1 SHDN
© 2007 Microchip Technology Inc.
DS22061A-page 1
MCP1602
Typical Application Circuit
4.7 µH
VIN
2.7V to 4.5V
4.7 µF
LX 7
6 VIN
10Ω
2 VCC
0.1 µF
4
AGND
1
SHDN
VOUT
1.5V @ 500 mA
4.7 µF
VFB 5
PGND 8
PG 3
MCP1602
RPULLUP
Processor
Reset
ON
OFF
VIN
DS22061A-page 2
© 2007 Microchip Technology Inc.
MCP1602
Functional Block Diagram
VCC
UVLO
VIN
VREF
Band
Gap
Thermal
Shutdown
UVLO
Soft Start
SHDN
ILIMPWM
TSD
ILIMPFM
IPK Limit
IPEAKPWM
Disable
Switcher
IPEAKPFM
Slope
Comp
OSC
-ILPK
S
Q
POFF
LX
NOFF
Switch Drive
R
Q
Logic and Timing
PWM/PFM
PFM Error Amp
PWM/PFM
Logic
PGND
IPEAKPFM
VREF
IPEAKPWM
PWM Error Amp
EA
-ILPK
-IPK Limit
VREF
VREF
VCC
PG
OV Threshold
PG Generator
with Delay
VFB / VOUT
AGND
UV Threshold
VOUT
© 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 †
VIN - AGND ......................................................................+6.0V
All Other I/O .............................. (AGND - 0.3V) to (VIN + 0.3V)
LX to PGND ............................................. -0.3V to (VIN + 0.3V)
Output Short Circuit Current..................................Continuous
Power Dissipation (Note 6) ..........................Internally Limited
Storage Temperature.................................... -65oC to +150oC
Ambient Temp. with Power Applied................ -40oC to +85oC
Operating Junction Temperature.................. -40oC to +125oC
ESD Protection On All Pins:
HBM..............................................................................3 kV
MM...............................................................................200V
DC CHARACTERISTICS
Electrical Characteristics: Unless otherwise indicated, VIN = 3.6V, COUT = CIN = 4.7 µF, L = 4.7 µH,
VOUT(ADJ) = 1.8V, IOUT = 100 mA, TA = +25°C. Boldface specifications apply for the TA range of -40oC to +85oC.
Parameters
Sym
Min
Typ
Max
Units
VIN
2.7
—
5.5
V
Conditions
Input Characteristics
Input Voltage
Note 1
IOUT
500
—
—
mA
Note 1
Shutdown Current
IIN_SHDN
—
0.05
1
µA
SHDN = GND
Quiescent Current
IQ
—
45
60
µA
SHDN = VIN, IOUT = 0 mA
Maximum Output Current
Shutdown/UVLO/Thermal Shutdown Characteristics
SHDN, Logic Input Voltage Low
VIL
—
—
15
%VIN
VIN = 2.7V to 5.5V
SHDN, Logic Input Voltage High
VIH
45
—
—
%VIN
VIN = 2.7V to 5.5V
SHDN, Input Leakage Current
Undervoltage Lockout
Undervoltage Lockout Hysteresis
VL_SHND
-1.0
±0.1
1.0
µA
VIN = 2.7V to 5.5V, SHDN = AGND
UVLO
2.40
2.55
2.70
V
VIN Falling
UVLOHYS
—
200
—
mV
TSHD
—
150
—
°C
Note 5, Note 6
TSHD-HYS
—
10
—
°C
Note 5, Note 6
VOUT
0.8
—
4.5
V
Note 2
Reference Feedback Voltage
VFB
—
0.8
—
V
Feedback Input Bias Current
IVFB
—
-1.5
—
nA
Thermal Shutdown
Thermal Shutdown Hysteresis
Output Characteristics
Adjustable Output Voltage
Range
Note 1:
2:
3:
4:
5:
6:
7:
The minimum VIN has to meet two conditions: VIN ≥ 2.7V and VIN ≥ VOUT + 0.5V.
Reference Feedback Voltage Tolerance applies to adjustable output voltage setting.
VR 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. TA, TJ, θJA). Exceeding the maximum
allowable power dissipation causes the device to initiate thermal shutdown.
The internal MOSFET switches have an integral diode from the LX pin to the VIN pin, and from the LX 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, VIN = 3.6V, COUT = CIN = 4.7 µF, L = 4.7 µH,
VOUT(ADJ) = 1.8V, IOUT = 100 mA, TA = +25°C. Boldface specifications apply for the TA range of -40oC to +85oC.
Parameters
Sym
Min
Typ
Max
Output Voltage Tolerance Fixed
VOUT
Line Regulation
VLINE-
Load Regulation
VLOAD-
Units
-2.5
VR
+2.5
%
—
0.3
—
%/V
—
0.4
—
%
FOSC
1.6
2.0
2.4
MHz
TSS
—
0.5
—
ms
TR = 10% to 90%
RDSon P-Channel
RDSon-P
—
450
—
mΩ
IP = 100 mA
RDSon N-Channel
RDSon-N
—
450
—
mΩ
IN = 100 mA
ILX
-1.0
±0.01
1.0
µA
SHDN = 0V, VIN = 5.5V, LX = 0V,
LX = 5.5V
Positive Current Limit Threshold +ILX(MAX)
Power-Good (PG)
—
700
—
mA
Note 7
Voltage Range
VPG
1.0
1.2
—
5.5
5.5
V
PG Threshold High
VTH_H
—
94
96
% of
VOUT
On Rising VOUT
PG Threshold Low
VTH_L
89
92
—
% of
VOUT
On Falling VOUT
PG Threshold Hysteresis
VTH_HYS
—
2
—
% of
VOUT
PG Threshold Tempco
ΔVTH/ΔT
—
30
—
ppm/°C
PG Delay
tRPD
—
165
—
µs
VOUT = (VTH_H + 100 mV) to
(VTH_L - 100 mV)
PG Active Time-out Period
tRPU
140
262
560
ms
VOUT = (VTH_L - 100 mV) to
(VTH_H + 100 mV), ISINK = 1.2mA
PG_VOL
—
—
0.2
V
REG
REG
Internal Oscillator Frequency
Start Up Time
LX Pin Leakage Current
PG Output Voltage Low
Note 1:
2:
3:
4:
5:
6:
7:
Conditions
Note 3
VIN = VR + 1V to 5.5V,
IOUT = 100 mA
VIN = VR +1.5V,
ILOAD = 100 mA to 500 mA, Note 1
TA = 0°C to +70°C
TA = -40°C to +85°C
VIN ≤ 2.7V, ISINK = 100 µA
VOUT = VTH_L - 100 mV,
IPG = 1.2 mA, VIN > 2.7V
IPG = 100 µA, 1.0 < VIN < 2.7V
The minimum VIN has to meet two conditions: VIN ≥ 2.7V and VIN ≥ VOUT + 0.5V.
Reference Feedback Voltage Tolerance applies to adjustable output voltage setting.
VR 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. TA, TJ, θJA). Exceeding the maximum
allowable power dissipation causes the device to initiate thermal shutdown.
The internal MOSFET switches have an integral diode from the LX pin to the VIN pin, and from the LX 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
MCP1602
TEMPERATURE SPECIFICATIONS
Electrical Specifications: Unless otherwise indicated, all limits are specified for: VIN + 2.7V to 5.5V
Parameters
Sym
Min
Typ
Max
Units
Conditions
Operating Junction Temperature
Range
TJ
-40
—
+125
°C
Storage Temperature Range
TA
-65
—
+150
°C
Maximum Junction Temperature
TJ
—
—
+150
°C
Thermal Resistance, 8L-MSOP
θJA
—
211
—
°C/W
Typical 4-layer Board with
Internal Ground Plane
Thermal Resistance, 8L-3x3 DFN
θJA
—
60
—
°C/W
Typical 4-layer Board with
Internal Ground Plane and
2-Vias in Thermal Pad
Temperature Ranges
Steady State
Transient
Package Thermal Resistances
DS22061A-page 6
© 2007 Microchip Technology Inc.
MCP1602
2.0
TYPICAL PERFORMANCE CURVES
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, COUT = CIN = 4.7 µF, L = 4.7 µH, VOUT(ADJ) = 1.8V, ILOAD = 100 mA,
TA = +25°C. Adjustable or fixed output voltage options can be used to generate the Typical Performance Characteristics.
55
VOUT = 1.8V
Quiescent Current (µA)
Quiescent Current (µA)
60
55
VIN = 5.5V
50
45
VIN = 3.6V
40
VIN = 4.2V
35
30
-40 -25 -10
5
TA = +25°C
TA = +90°C
50
45
TA = -40°C
40
35
30
20 35 50 65 80 95 110 125
2.7
3.05
3.4
3.75
Ambient Temperature (oC)
FIGURE 2-1:
FIGURE 2-4:
4.8
5.15
5.5
IQ vs. Input Voltage.
100
VOUT = 1.2V
95
IOUT = 100 mA
90
85
80
IOUT = 300 mA
75
VIN = 3.6V
90
Efficiency (%)
Efficiency (%)
4.45
Input Voltage (V)
IQ vs. Ambient Temperature.
100
IOUT = 500 mA
70
80
VIN = 3.0V
70
60
50
40
VIN = 4.2V
30
65
3.0
3.2
3.4
3.6
3.8
4.0
VOUT = 1.2V
20
4.2
0.1
1
Input Voltage (V)
FIGURE 2-2:
(VOUT = 1.2V).
Efficiency vs. Input Voltage
1000
Efficiency vs. Output Load
100
VOUT = 1.8V
90
85
IOUT = 300 mA
IOUT = 500 mA
80
VIN = 3.6V
90
IOUT = 100 mA
75
Efficiency (%)
95
10
100
Output Current (mA)
FIGURE 2-5:
(VOUT = 1.2V).
100
Efficiency (%)
4.1
80
70
VIN = 3.0V
60
50
40
VIN = 4.2V
30
70
3.0
3.2
3.4
3.6
3.8
4.0
4.2
VOUT = 1.8V
20
0.1
Input Voltage (V)
FIGURE 2-3:
(VOUT = 1.8V).
Efficiency vs. Input Voltage
© 2007 Microchip Technology Inc.
1
10
100
1000
Output Current (mA)
FIGURE 2-6:
(VOUT = 1.8V).
Efficiency vs. Output Load
DS22061A-page 7
MCP1602
Typical Performance Curves (Continued)
Note: Unless otherwise indicated, VIN = SHDN = 3.6V, COUT = CIN = 4.7 µF, L = 4.7 µH, VOUT(ADJ) = 1.8V, ILOAD = 100 mA,
TA = +25°C. Adjustable or fixed output voltage options can be used to generate the Typical Performance Characteristics.
100.0
100
VOUT = 3.3V
IOUT = 100 mA
95.0
IOUT = 300 mA
92.5
90.0
VIN = 4.2V
90
Efficiency (%)
Efficiency (%)
97.5
IOUT = 500 mA
87.5
80
70
60
50
40
30
85.0
VIN = 5.5V
4.2
4.4
4.6
4.8
5.0
5.2
5.4
0.1
1
Input Voltage (V)
FIGURE 2-7:
(VOUT = 3.3V).
Efficiency vs. Input Voltage
FIGURE 2-10:
(VOUT = 3.3V).
100
1000
Efficiency vs. Output Load
96
PG Threshold (% of V OUT )
PG Active Time-Out (ms)
10
Output Current (mA)
340
320
300
280
260
240
220
200
95
PG Threshold High
94
93
92
91
90
PG Threshold Low
89
88
-40 -25 -10
5
20 35 50 65 80 95 110 125
-40 -25 -10
Ambient Temperature (°C)
5
20 35 50 65 80 95 110 125
Ambient Temperature (°C)
FIGURE 2-8:
PG Active Time-out vs.
Ambient Temperature.
FIGURE 2-11:
PG Threshold Voltage vs.
Ambient Temperature.
1.85
0.832
0.828
Output Voltage (V)
Feedback Voltage (V)
VOUT = 3.3V
20
0.824
0.820
0.816
Ambient Temperature (°C)
FIGURE 2-9:
Feedback Voltage vs.
Ambient Temperature.
DS22061A-page 8
125
95
110
80
65
50
35
5
20
-10
-25
-40
0.812
1.84
1.83
1.82
1.81
0
50 100 150 200 250 300 350 400 450 500
Output Current (mA)
FIGURE 2-12:
Output Voltage vs. Load
Current (VOUT = 1.8V).
© 2007 Microchip Technology Inc.
MCP1602
Typical Performance Curves (Continued)
Note: Unless otherwise indicated, VIN = SHDN = 3.6V, COUT = CIN = 4.7 µF, L = 4.7 µH, VOUT(ADJ) = 1.8V, ILOAD = 100 mA,
TA = +25°C. Adjustable or fixed output voltage options can be used to generate the Typical Performance Characteristics.
Switching Frequency (MHz)
Switching Frequency (MHz)
2.00
1.98
1.96
1.94
1.92
1.90
-40 -25 -10 5 20 35 50 65 80 95 110 125
Ambient Temperature (°C)
FIGURE 2-13:
Switching Frequency vs.
Ambient Temperature.
2.05
2.00
1.95
1.90
1.85
2.70 3.05 3.40 3.75 4.10 4.45 4.80 5.15 5.50
Input Voltage (V)
FIGURE 2-16:
Input Voltage.
0.6
Switching Frequency vs.
0.7
0.5
P-Channel
0.4
N-Channel
0.3
0.2
2.70 3.05 3.40 3.75 4.10 4.45 4.80 5.15 5.50
Switch Resistance (Ω)
Switch Resistance (Ω)
2.10
0.6
0.5
P-Channel
0.4
N-Channel
0.3
0.2
-40 -25 -10
5
20
35
50
65
80
95 110 125
Ambient Temperature (°C)
Input Voltage (V)
FIGURE 2-14:
Voltage.
Switch Resistance vs. Input
FIGURE 2-17:
Switch Resistance vs.
Ambient Temperature.
FIGURE 2-15:
Waveform.
Output Voltage Startup
FIGURE 2-18:
Waveform.
© 2007 Microchip Technology Inc.
Heavy Load Switching
DS22061A-page 9
MCP1602
Typical Performance Curves (Continued)
Note: Unless otherwise indicated, VIN = SHDN = 3.6V, COUT = CIN = 4.7 µF, L = 4.7 µH, VOUT(ADJ) = 1.8V, ILOAD = 100 mA,
TA = +25°C. Adjustable or fixed output voltage options can be used to generate the Typical Performance Characteristics.
FIGURE 2-19:
Waveform.
Light Load Switching
FIGURE 2-20:
Output Voltage Load Step
Response vs. Time.
DS22061A-page 10
FIGURE 2-21:
Output Voltage Line Step
Response vs. Time.
FIGURE 2-22:
Power-Good Output Timing.
© 2007 Microchip Technology Inc.
MCP1602
3.0
PIN DESCRIPTIONS
The descriptions of the pins are listed in Table 3-1.
TABLE 3-1:
PIN FUNCTION TABLE
MSOP
DFN
Sym
1
1
SHDN
2
2
VCC
Analog Input Supply Voltage Pin
3
3
PG
Power Good Output Pin
4
4
AGND
5
5
VFB/VOUT
6
6
VIN
Input Supply Voltage Pin
7
7
LX
Buck Inductor Output Pin
8
8
PGND
—
Exposed
Pad
EP
3.1
Description
Shutdown Input Pin
Analog Ground Pin
Feedback Voltage (Adjustable Version) / Output Voltage (Fixed Version) Pin
Power Ground Pin
For the DFN package, the center exposed pad is a thermal path to remove
heat from the device. Electrically this pad is at ground potential and should
be connected to AGND
Shutdown Control Input Pin
(SHDN)
3.6
Power Supply Input Voltage Pin
(VIN)
The SHDN pin is a logic-level input used to enable or
disable the device. A logic high (>45% of VIN) will
enable the regulator output. A logic-low (
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