NCP3101C
Wide Input Voltage
Synchronous Buck Converter
The NCP3101C is a high efficiency, 6 A DC−DC buck converter
designed to operate from a 5 V to 12 V supply. The device is capable
of producing an output voltage as low as 0.8 V. The NCP3101C can
continuously output 6 A through MOSFET switches driven by an
internally set 275 kHz oscillator. The 40−pin device provides an
optimal level of integration to reduce size and cost of the power
supply. The NCP3101C also incorporates an externally compensated
transconductance error amplifier and a capacitor programmable
soft−start function. Protection features include programmable short
circuit protection and input under voltage lockout (UVLO). The
NCP3101C is available in a 40−pin QFN package.
Features
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MARKING
DIAGRAM
QFN40, 6x6
CASE 485AK
1 40
A
WL
YY
WW
G
NCP3101C
AWLYYWWG
•
•
•
•
•
•
•
•
•
•
•
•
Split Power Rail 2.7 V to 18 V on PWRVCC
275 kHz Internal Oscillator
Greater Than 90% Max Efficiency
Boost Pin Operates to 35 V
Voltage Mode PWM Control
0.8 V
$1%
Internal Reference Voltage
Adjustable Output Voltage
Capacitor Programmable Soft−Start
85% Max Duty Cycle
Input Undervoltage Lockout
Resistor Programmable Current Limit
These are Pb−Free Devices
= Assembly Location
= Wafer Lot
= Year
= Work Week
= Pb−Free Package
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 24 of this data sheet.
Applications
•
Servers / Networking
•
DSP and FPGA Power Supply
•
DC−DC Regulator Modules
D1
CBST
CPHS BST
PWRVCC
PWRPHS
PWRVCC
PWRPHS
EP
(EP)
VCC
PWRGND
CVCC
BG
COMP/DIS
RSET
CP
FC
AGND
(EP)
PWRGND
(EP)
FB
AGND
R2
LO
CO
R1
100
95
90
EFFICIENCY (%)
85
80
75
70
65
60
55
50
0
1
2
V
IN
= 5 V
V
IN
= 12 V
CIN
CC
V
OUT
= 3.3 V
3
I
OUT
(A)
4
5
6
Figure 1. Typical Application Diagram
Figure 2. Efficiency
©
Semiconductor Components Industries, LLC, 2011
August, 2011
−
Rev. 1
1
Publication Order Number:
NCP3101C/D
NCP3101C
VCC
13
FB
16
POR
UVLO
BST
24
TGOUT
21
TGIN
25
PWRVCC
26−34
−
+
V
ref
0.8 V
−
+
FAULT
R
PWM
OUT
S
Q
PWRPHS
1−4
36−40
CPHS
22
CLOCK
COMP
DIS
RAMP
17
VCC
OSC
FAULT
OSC
LATCH
50 mV
−550
mV
VOCTH
+
−
2V
−
+
400 mV
FAULT
VOCTH
SET
10
mA
−
+
2V
CPHS
−
+
14,15,19,20,23
AGND
35
BG
5−12
PWRGND
Figure 3. Detailed Block Diagram
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2
NCP3101C
PWRPHS
PWRPHS
PWRPHS
PWRPHS
PWRPHS
BG
PWRVCC
PWRVCC
PWRVCC
PWRVCC
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
PWRPHS 1
PWRPHS 2
PWRPHS 3
PWRPHS 4
PWRGND 5
PWRGND 6
PWRGND 7
PWRGND 8
PWRGND 9
PWRGND 10
PWRPHS
PWRVCC
AGND
PWRVCC
PWRVCC
PWRVCC
PWRVCC
PWRVCC
TGIN
BST
AGND
CPHS
TGOUT
Figure 4. Pin Connections
Table 1. PIN FUNCTION DESCRIPTION
Pin No
1−4, 36−40
5−12
Symbol
PWRPHS
PWRGND
Description
Power phase node (PWRPHS). Drain of the low side power MOSFET.
Power ground. High current return for the low−side power MOSFET. Connect
PWRGND with large copper areas to the input and output supply returns, and
negative terminals of the input and output capacitors.
Supply rail for the internal circuitry. Operating supply range is 4.5 V to 13.2 V.
Decouple with a 1
mF
capacitor to GND. Ensure that this decoupling capacitor is
placed near the IC.
IC ground reference. All control circuits are referenced to these pins.
The inverting input pin to the error amplifier. Use this pin in conjunction with the
COMP pin to compensate the voltage−control feedback loop. Connect this pin to the
output resistor divider (if used) or directly to output voltage.
Compensation or disable pin. The output of the error amplifier (EA) and the
non−inverting input of the PWM comparator. Use this pin in conjunction with the FB
pin to compensate the voltage−control feedback loop. The compensation capacitor
also acts as a soft start capacitor. Pull the pin below 400 mV to disable controller.
Not Connected. The pin can be connected to AGND or not connected.
High side MOSFET driver output.
The controller phase sensing for short circuit protection.
Supply rail for the floating top gate driver. To form a boost circuit, use an external
diode to bring the desired input voltage to this pin (cathode connected to BST pin).
Connect a capacitor (C
BST
) between this pin and the CPHS pin.
High side MOSFET gate.
Input supply pin for the high side MOSFET. Connect VCCPWR to the VCC pin or
power separately for split rail application..
The current limit set pin.
13
VCC
14,15,19,20,23
16
AGND
FB
17
COMP/DIS
18
21
22
24
NC
TGOUT
CPHS
BST
25
26−34
35
TGIN
PWRVCC
BG
Table 2. ABSOLUTE MAXIMUM RATINGS
Pin Name
Main Supply Voltage Control Input
Main Supply Voltage Power Input
Bootstrap Supply Voltage vs Ground
Bootstrap Supply Voltage vs Ground (spikes < =
50 ns)
Symbol
V
CC
PWRVCC
V
BST
V
BST_spike
Min
−0.3
−0.3
−0.3
−5.0
Max
15
30
35
40
Unit
V
V
V
V
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PWRGND
PWRGND
VCC
AGND
AGND
FB
COMP
NC
AGND
AGND
11
12
13
14
15
16
17
18
19
20
PWRGND
NCP3101C
Table 2. ABSOLUTE MAXIMUM RATINGS
Pin Name
Bootstrap Pin Voltage vs V
PWRPHS
High Side Switch Max DC Current
V
PWRPHS
Pin Voltage
V
PWRPHS
Pin Voltage (spikes < 50 ns)
CPHASE Pin Voltage
CPHASE Pin Voltage (spikes < 50 ns)
Current Limit Set and Bottom Gate
Current Limit Set and Bottom Gate (spikes < 200 ns)
Top Gate vs Ground
Top Gate vs Phase
Top Gate vs Phase (spikes < 200 ns)
FB Pin Voltage
COMP/DISABLE
Rating
Thermal Resistance, Junction−to−Ambient (Note 2)
Thermal Resistance, Junction−to−Case (Note 2) at
85°C
Continuous Power Distribution (T
A
= +85°C)
Storage Temperature Range
Junction Operating Temperature
Lead Temperature Soldering (10 sec):
Reflow (SMD styles only) Pb−Free (Note 1)
Symbol
V
BST
−V
PWRPHS
I PHS
V
PWRPHS
V
PWRPHSSP
V
CPHS
V
CPHSTR
V
BG
V
BGSP
V
TG
V
TG
V
TGSP
V
FB
VCOMP/DIS
Symbol
R
qJA
R
qJC
P
D
T
stg
T
J
RF
Min
−0.3
0
−0.7
−5
−0.7
−5
−0.3
−2.0
−0.3
−0.3
−2.0
−0.3
−0.3
Max
15
7.5
30
40
30
40
V
CC
< V
BG
< 15
V
CC
< V
BGSP
< 15
30
V
CC
< V
TG
< 15
V
CC
< V
TGSP
< 15
V
CC
< V
FB
< 6.0
V
CC
< V
COMP/DIS
< 6.0
Symbol
35
5
1.8
−55
to 150
−40
to 150
260 peak
Unit
V
A
V
V
V
V
V
V
V
V
V
V
V
Unit
°C/W
°C/W
W
°C
°C
°C
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the
Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect
device reliability.
NOTE: These devices have limited built−in ESD protection. The devices should be shorted together or the device placed in conductive
foam during storage or handling to prevent electrostatic damage to the device.
1. 60−180 seconds minimum above 237°C
2. Based on 110 * 100 mm double layer PCB with 35
mm
thick copper plating.
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NCP3101C
Table 3. ELECTRICAL CHARACTERISTICS
(−40°C < T
J
< 125°C; VCC =12 V, BST
−
PHS = 12 V, BST = 12 V, PHS = 24 V,
Characteristic
Power Power Channel
Input Voltage Range
Boost Voltage Range
SUPPLY CURRENT
Quiescent Supply Current
Quiescent Supply Current
V
CC
Supply Current
V
CC
Supply Current
Boost Quiescent Current
Shutdown Supply Current
UNDER VOLTAGE LOCKOUT
V
CC
UVLO Threshold
V
CC
UVLO Hysteresis
BST UVLO Threshold Rising
BST UVLO Threshold Falling
SWITCHING REGULATOR
VFB Feedback Voltage,
Control Loop in Regulation
Oscillator Frequency
Ramp−Amplitude Voltage
Minimum Duty Cycle
Maximum Duty Cycle
TG Falling to BG Rising Delay
BG Falling to TG Rising Delay
PWM COMPENSATION
Transconductance
Open Loop DC Gain
Output Source Current
Output Sink Current
Input Bias Current
ENABLE
Enable Threshold (Falling)
SOFT−START
Delay to Soft−Start
SS Source Current
Switch Over Threshold
OVER−CURRENT PROTECTION
OCSET Current Source
OC Threshold
OC Switch−Over Threshold
Fixed OC Threshold
PWM OUTPUT STAGE
High−Side Switch On−Resistance
Low−Side Switch On−Resistance
V
CC
= 12 V I
D
= 1 A
V
CC
= 12 V I
D
= 1 A
−
−
18
18
−
−
mW
mW
Sourced from BG Pin before Soft−Start
R
BG
= 5 kW
−
−
−
−
10
50
700
99
−
−
−
−
mA
mV
mV
mV
V
FB
< 0.8 V
V
FB
= 0.8 V
1
−
−
−
10.6
100
5
−
−
ms
mA
% of
Vref
0.37
0.4
.43
V
Guaranteed by design
V
FB
< 0.8 V
V
FB
> 0.8 V
3.1
55
80
80
−
−
70
140
131
0.160
3.5
−
200
200
1.0
mS
DB
mA
mA
V
CC
= 12 V, T
G
< 2.0 V, B
G
> 2.0 V
V
CC
= 12 V, B
G
< 2.0 V, T
G
> 2.0 V
0°C < T
J
< 70°C, 4.5 V < V
CC
< 13.2 V
−40°C
< T
J
< 125°C, 4.5 < V
CC
< 13.2 V
0°C < T
J
< 70°C, 4.5 V < V
CC
< 13.2 V
−40°C
< T
J
< 125°C, 4.5 < V
CC
< 13.2 V
0.792
0.788
250
233
0.8
−
0.800
0.800
275
275
1.1
7.0
88.5
46
41
0.808
0.812
300
317
1.4
−
V
kHz
V
%
%
ns
ns
V
CC
Rising Edge
−
BST Rising
3.8
−
−
−
−
364
3.82
3.71
4.3
−
−
−
V
mV
V
V
V
FB
= 0.85 V V
COMP
= 0.4 V,
No Switching, V
CC
= 13.2 V
V
FB
= 0.85 V V
COMP
= 0.4 V
No Switching, V
CC
= 5.0 V
V
FB
= V
COMP
= 1 V, Switching, V
CC
= 13.2 V
V
FB
= V
COMP
= 1 V, Switching, V
CC
= 5 V
V
FB
= 0.85 V, No Switching, V
CC
= 13.2 V
V
FB
= 1 V, VCOMP= 0 V, No Switching, V
CC
= 13.2 V
−
4.1
3.2
9.1
4.8
63
4.1
−
15
8.0
mA
mA
mA
mA
mA
mA
Conditions
PWRV
CC
−
GND
V
CC
−
GND
V
BST
−
GND
Min
2.7
4.5
4.5
Typ
Max
18
13.2
26.5
Unit
V
V
V
for min/max values unless otherwise noted).
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