MCP14628
2A Synchronous Buck Power MOSFET Driver
Features
• Dual Output MOSFET Driver for Synchronous
Applications
• High Peak Output Current: 2A (typical)
• Adaptive Cross Conduction Protection
• Internal Bootstrap Blocking Device
• +36V BOOT Pin Maximum Rating
• Enhanced Light Load Efficiency Mode
• Low Supply Current: 80 µA (typical)
• High Capacitive Load Drive Capability:
- 3300 pF in 10 ns (typical)
• Tri-State PWM Pin for Power Stage Shutdown
• Input Voltage Undervoltage Lockout Protection
• Space Saving Packages:
- 8-Lead SOIC
- 8-Lead 3x3 DFN
General Description
The MCP14628 is a dual MOSFET gate driver
designed to optimally drive two N-Channel MOSFETs
arranged in a non-isolated synchronous buck converter
topology. With the capability to source 2A peaks
typically from both the high-side and low-side drives,
the MCP14628 is an ideal companion to buck control-
lers that lack integrated gate drivers. Additionally,
greater design flexibility is offered by allowing the gate
drivers to be placed close to the power MOSFETs.
The MCP14628 features the capability to sink 3.5A
peak typically for the low-side gate drive. This allows
the MCP14628 the capability of holding off the low-side
power MOSFET during the rising edge of the PHASE
node. Internal adaptive cross conduction protection
circuitry is also used to mitigate both external power
MOSFETs from simultaneously conducting.
The low resistance pull-up and pull-down drives allow
the MCP14628 to quickly transition a 3300 pF load in
typically 10 ns and with a propagation time of typically
20 ns. Bootstrapping for the high-side drive is internally
implemented which allows for a reduced system cost
and design complexity.
The PWM input to the MCP14628 can be tri-stated to
force both drive outputs low for true power stage
shutdown. Light load system efficiency is improved by
using the diode emulation feature of the MCP14628.
When the FCCM pin is grounded, diode emulation
mode is entered. In this mode, discontinuous conduc-
tion is allowed by sensing when the inductor current
reach zero and turning off the low-side power
MOSFET.
Applications
• High Efficient Synchronous DC/DC Buck
Converters
• High Current Low Output Voltage Synchronous
DC/DC Buck Converters
• High Input Voltage Synchronous DC/DC Buck
Converters
• Core Voltage Supplies for Microprocessors
Package Types
8-Lead SOIC
1
2
3
4
8
7
6
5
HIGHDR
BOOT
PWM
GND
1
2
3
4
8-Lead DFN
HIGHDR
BOOT
PWM
GND
PHASE
FCCM
V
CC
LOWDR
8
7
6
5
PHASE
FCCM
V
CC
LOWDR
Note 1:
Exposed pad on the DFN is electrically isolated.
©
2008 Microchip Technology Inc.
DS22083A-page 1
MCP14628
Typical Application Schematic
C
BOOT
V
SUPPLY
= 12V
BOOT
V
CC
= 5V
CURRENT
SENSE
Q
H
MCP14628
V
CC
FCCM
CONTROL
FCCM
PWM
UGATE
PHASE
LGATE
GND
Q
L
VEXT
MCP1630
V
CC
CURRENT
SENSE
CS
OSC IN
FB
COMP
V
REF
GND
REFERENCE VOLTAGE
OSCILLATOR
FROM MCU
Functional Block Diagram
V
CC
BOOT
FCCM
Level
Shift
R
HIGHDR
PWM
R
Control
Logic &
Protection
V
CC
PHASE
LOWDR
GND
DS22083A-page 2
©
2008 Microchip Technology Inc.
MCP14628
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
CC
, Device Supply Voltage............................. -0.3V to +7.0V
V
BOOT
, BOOT Voltage.................................... -0.3V to +36.0V
V
PHASE
, Phase Voltage........... V
BOOT
- 7.0V to V
BOOT
+ 0.3V
V
FCCM
, FCCM Voltage ........................... -0.3V to V
CC
+ .0.3V
V
PWM
, PWM Voltage ............................... -0.3V to V
CC
+ 0.3V
V
UGATE
, UGATE Voltage ....... V
PHASE
- 0.3V to V
BOOT
+ 0.3V
V
LGATE
, LGATE Voltage .......................... -0.3V to V
CC
+ 0.3V
ESD Protection on all Pins ....................................2 kV (HBM)
DC CHARACTERISTICS
Electrical Specifications:
Unless otherwise noted, V
CC
= 5V, T
J
= -40°C to +125°C
Parameters
V
CC
Supply Requirements
Recommended Operating Range
Bias Supply Voltage
UVLO (Rising V
CC
)
UVLO (Falling V
CC
)
Hysteresis
PWM Input Requirements
PWM Input Current
PWM Rising Threshold
PWM Falling Threshold
Tri-State Shutdown Hold-off Time
FCCM input Requirements
FCCM Low Threshold
FCCM High Threshold
Output Requirements
High Drive Source Resistance
High Drive Sink Resistance
High Drive Source Current
High Drive Sink Current
Low Drive Source Resistance
Low Drive Sink Resistance
Low Drive Source Current
Low Drive Sink Current
Note 1:
2:
—
—
—
—
—
—
—
—
1.0
1.0
2.0
2.0
1
0.5
2.0
3.5
2.5
2.5
—
—
2.5
1.0
—
—
Ω
Ω
A
A
Ω
Ω
A
A
500 mA source current,
Note 1
500 mA sink current,
Note 1
Note 1
Note 1
500 mA source current,
Note 1
500 mA sink current,
Note 1
Note 1
Note 1
0.50
—
—
—
—
2.0
V
V
t
TSSHD
I
PWM
—
—
0.70
3.50
100
250
-250
1.00
3.80
175
—
—
1.30
4.10
250
µA
µA
V
V
ns
T
A
= +25°C,
Note 2
V
PWM
= 5V
V
PWM
= 0V
V
CC
I
VCC
4.5
—
—
2.40
—
5.0
80
3.40
2.90
500
5.5
—
3.90
—
—
V
µA
V
V
mV
PWM pin floating,
V
FCCM
= 5V
Sym
Min
Typ
Max
Units
Conditions
Parameter ensured by design, not production tested.
See
Figure 4-1
for parameter definition.
©
2008 Microchip Technology Inc.
DS22083A-page 3
MCP14628
DC CHARACTERISTICS (CONTINUED)
Electrical Specifications:
Unless otherwise noted, V
CC
= 5V, T
J
= -40°C to +125°C
Parameters
Switching Times
HIGHDR Rise Time
LOWDR Rise Time
HIGHDR Fall Time
LOWDR Fall Time
HIGHDR Turn-off Propagation
Delay
LOWDR Turn-off Propagation
Delay
HIGHDR Turn-on Propagation
Delay
LOWDR Turn-on Propagation
Delay
Tri-State Propagation Delay
t
RH
t
RL
t
FH
t
FL
t
PDLH
t
PDLL
t
PDHH
t
PDHL
t
PTS
—
—
—
—
—
—
10
10
—
10
10
10
6.0
15
16
18
22
35
—
—
—
—
—
—
30
30
—
—
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
C
L
= 3.3nF,
Note 1, Note 2
C
L
= 3.3nF,
Note 1, Note 2
C
L
= 3.3nF,
Note 1, Note 2
C
L
= 3.3nF,
Note 1, Note 2
No Load,
Note 2
No Load,
Note 2
No Load,
Note 2
No Load,
Note 2
No Load,
Note 2
FCCM pin low
Note 1
Sym
Min
Typ
Max
Units
Conditions
Minimum LOWDR On Time in DCM t
LGMIN
—
400
Note 1:
Parameter ensured by design, not production tested.
2:
See
Figure 4-1
for parameter definition.
TEMPERATURE CHARACTERISTICS
Electrical Specifications:
Unless otherwise noted, all parameters apply with V
CC
= 5V.
Parameter
Temperature Ranges
Specified Temperature Range
Maximum Junction Temperature
Storage Temperature
Package Thermal Resistances
Thermal Resistance, 8L-SOIC
Thermal Resistance, 8L-DFN (3x3)
θ
JA
θ
JA
—
—
149.5
60.0
—
—
°C/W
°C/W
Typical Four-layer board
with vias to ground plane
T
A
T
J
T
A
-40
—
-65
—
—
—
+85
+150
+150
°C
°C
°C
Sym
Min
Typ
Max
Units
Comments
DS22083A-page 4
©
2008 Microchip Technology Inc.
MCP14628
2.0
Note:
TYPICAL PERFORMANCE CURVES
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, T
A
= +25°C with V
CC
= 5.0V.
25
t
RH
20
Rise Time (ns)
15
10
5
0
0
1500
3000
4500
6000
7500
Capacitive Load (pF)
t
RL
Fall Time (ns)
20
15
10
t
FL
5
0
0
1500
3000
4500
6000
7500
Capacitive Load (pF)
25
t
FH
FIGURE 2-1:
Load.
14
13
12
Time (ns)
11
10
9
8
7
6
-40 -25 -10
5
Rise Times vs. Capacitive
FIGURE 2-4:
Load.
12
Fall Times vs. Capacitive
C
LOAD
= 3,300 pF
t
RH
Time (ns)
11
10
C
LOAD
= 3,300 pF
t
RL
t
FH
9
8
7
6
5
4
t
FL
20 35 50 65 80 95 110 125
Temperature (°C)
-40 -25 -10
5
20 35 50 65 80 95 110 125
Temperature (°C)
FIGURE 2-2:
vs. Temperature.
24
Propagation Delay (ns)
22
20
18
16
14
12
10
-40 -25 -10
5
t
PDHH
HIGHDR Rise and Fall Time
FIGURE 2-5:
vs. Temperature.
30
LOWDR Rise and Fall Time
C
LOAD
= 3,300 pF
Time (ns)
28
26
24
22
20
18
16
14
12
C
LOAD
= 3,300 pF
t
PDLH
t
PDHL
t
PDLL
20 35 50 65 80 95 110 125
Temperature (°C)
-40 -25 -10
5
20 35 50 65 80 95 110 125
Temperature (°C)
FIGURE 2-3:
vs. Temperature.
HIGHDR Propagation Delay
FIGURE 2-6:
vs. Temperature.
LOWDR Propagation Delay
©
2008 Microchip Technology Inc.
DS22083A-page 5
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