NCP1511
Up to 500 mA, High
Efficiency Synchronous
Step−Down DC−DC Converter
in Chip Scale Package
The NCP1511 step−down PWM DC−DC converter is optimized
for portable applications powered from 1−cell Li−ion or 3−cell
Alkaline/NiCd/NiMH batteries. This DC−DC converter utilizes a
current−mode control architecture for easy compensation and better
line regulation. It also uses synchronous rectification to increase
efficiency and reduce external part count. The NCP1511 optimizes
efficiency in light load conditions when switched from a normal
PWM mode to a “pulsed switching” mode. The device also has a
built−in oscillator for the PWM circuitry, or it can be synchronized to
an external 500 kHz to 1000 kHz clock signal. Finally, it includes an
integrated soft−start, cycle−by−cycle current limiting, and thermal
shutdown protection. The NCP1511 is available in a chip scale
package.
Features
http://onsemi.com
9 PIN
MICRO BUMP
FC SUFFIX
CASE 499AC
= Device Code
= Assembly Location
= Year
= Work Week
MARKING
DIAGRAM
DAL
AYWW
A1
A1
XX
A
Y
WW
PIN CONNECTIONS
A1
A2
A3
B1
B2
B3
C1
C2
C3
Pin: A1. − GNDP
A2. − LX
A3. − VCC
B1. − SYNC
B2. − GNDA
B3. − FB
C1. − SHD
C2. − CB1
C3. − CB0
•
High Efficiency:
•
•
•
•
•
•
•
•
•
•
•
•
•
93% for 1.89 V Output at 3.6 V Input and 150 mA Load Current
92% for 1.89 V Output at 3.6 V Input and 300 mA Load Current
Digital Programmable Output Voltages: 1.0, 1.3, 1.5 or 1.89 V
Output Current up to 500 mA at V
in
= 3.6 V
Low Quiescent Current of 14
mA
in Pulsed Switching Mode
Low 0.1
mA
Shutdown Current
−30°C to 85°C Operation Temperature
Ceramic Input/Output Capacitor
9 Pin Chip Scale Package
Pb−Free Package is Available
Cellular Phones, Smart Phones and PDAs
Digital Still Cameras
MP3 Players and Portable Audio Systems
Wireless and DSL Modems
Portable Equipment
EFFICIENCY (%)
A3
C
in
10
mF
C1
A2
B3
C2
6.8
mH
V
out
C
out
22
mF
(Bottom View)
ORDERING INFORMATION
Device
NCP1511FCT1
NCP1511FCT1G
Package
Micro Bump
Micro Bump
(Pb−Free)
Shipping
†
3000 Tape & Reel
3000 Tape & Reel
Applications
†For information on tape and reel specifications,
including part orientation and tape sizes, please
refer to our Tape and Reel Packaging Specifications
Brochure, BRD8011/D.
100
90
80
Pulsed Mode
PWM Mode
V
in
2.5 V − 5.2 V
70
60
50
40
30
20
10
0
0.1
1
10
I
out
(mA)
VCC
LX
FB
SHD
B1
SYNC
CB1
CB0 and CB1
C3
Control Input
CB0
GNDA GNDP
B2
A1
V
in
= 3.6 V
V
out
= 1.5 V
T
A
= 25°C
100
1000
Figure 1. Typical Application Circuit
©
Semiconductor Components Industries, LLC, 2005
Figure 2. Efficiency vs. Output Current
1
Publication Order Number:
NCP1511/D
January, 2005 − Rev. 5
NCP1511
ISENS
COMPENSATION
RAMP
−
CMP
+
SENFET
ISENS
VCC
FB
−
OA
+
+
ILIM
CMP
−
DVR
Q1
LX
DAMPING
SWITCHING
CONTROL
FB
ZCL
−
CMP
+
Q2
DVR
PWM
−
CMP
+
GNDA
−
CMP
+
OVP
PM
CB0
CB1
CONTROL
BLOCK
(PWM,PM)
SELECT
LOGIC
BANDGAP
REFERENCE
AND SOFT
START
THERMAL
SHUTDOWN
GNDP
SHD
ENABLE
DETECT
MODE SELECTION
SYNC DETECT
AND
TIMING BLOCK
SYNC
Figure 3. Simplified Block Diagram
PIN FUNCTION DESCRIPTION
Pin No.
A1
A2
A3
B1
Symbol
GNDP
LX
V
CC
SYNC
Type
Power Ground
Analog Output
Analog Input
Analog Input
Description
Ground Connection for the NFET Power Stage.
Connection from Power Pass Elements to the Inductor.
Power Supply Input for Power and Analog V
CC
.
Synchronization input for the PWM converter. If a clock signal is present, the converter
uses the rising edge for the turn on. If this pin is low, the converter is in the Pulsed mode.
If this pin is high, the converter uses the internal oscillator for the PWM mode. This pin
contains an internal pull down resistor.
Ground connection for the Analog Section of the IC. This is the GND for the FB, Ref,
Sync, CB, and SHD pins.
Feedback Voltage from the Output of the Power Supply.
Enable for Switching Regulator. This Pin is Active High to enable the NCP1511. The SHD
Pin has an internal pull down resistor to force the converter off if this pin is not connected
to the external circuit.
Selects V
out
. This pin contains an internal pull up resistor.
Selects V
out
. This pin contains an internal pull down resistor.
B2
B3
C1
GNDA
FB
SHD
Analog Ground
Analog Input
Analog Input
C2
C3
CB1
CB0
Analog Input
Analog Input
http://onsemi.com
2
NCP1511
MAXIMUM RATINGS
Rating
Maximum Voltage All Pins
Maximum Operating Voltage All Pins
Thermal Resistance, Junction−to−Air (Note 1)
Operating Ambient Temperature Range
ESD Withstand Voltage
Moisture Sensitivity
Storage Temperature Range
Junction Operating Temperature
Human Body Model (Note 2)
Machine Model (Note 2)
Symbol
V
max
V
max
R
qJA
T
A
V
ESD
MSL
T
stg
T
J
Value
5.5
5.2
159
−30 to 85
> 2500
> 150
Level 1
−55 to 150
−30 to 125
°C
°C
Unit
V
V
°C/W
°C
V
Maximum ratings are those values beyond which device damage can occur. Maximum ratings applied to the device are individual stress limit values
(not normal operating conditions) and are not valid simultaneously. If these limits are exceeded, device functional operation is not implied, damage
may occur and reliability may be affected.
1. For the 9−Pin Micro Bump package, the R
qJA
is highly dependent of the PCB heatsink area. R
qJA
= 159°C/W with 50 mm
2
PCB heatsink area.
2. This device series contains ESD protection and exceeds the following tests:
Human Body Model, 100 pF discharge through a 1.5 kW following specification JESD22/A114.
Machine Model, 200 pF discharged through all pins following specification JESD22/A115.
Latchup as per JESD78 Class II: > 100 mA.
http://onsemi.com
3
NCP1511
ELECTRICAL CHARACTERISTICS
(V
in
= 3.6 V, Vo = 1.5 V, T
A
= 25°C, Fsyn = 600 kHz 50% Duty Cycle square wave for PWM
mode; T
A
= –30 to 85°C for Min/Max values, unless otherwise noted.
Characteristic
VCC Pin
Quiescent Current of Sync Mode, I
out
= 0 mA
Quiescent Current of PWM Mode, I
out
= 0 mA
Quiescent Current of Pulsed Mode, I
out
= 0 mA
Quiescent Current, SHD Low
Input Voltage Range (Note 3)
Sync Pin
Input Voltage
Frequency Operational Range
Minimum Synchronization Pulse Width
Maximum Synchronization Pulse Width
SYNC “H” Voltage Threshold
SYNC “L” Voltage Threshold
SYNC “H” Input Current, Vsync = 3.6 V
SYNC “L” Input Current, Vsync = 0 V
Output Level Selection Pins
Input Voltage
CB0, CB1 “H” Voltage Threshold
CB0, CB1 “L” Voltage Threshold
CB0 “H” Input Current, CB = 3.6 V
CB0 “L” Input Current, CB = 0 V
CB1 “H” Input Current, CB = 3.6 V
CB1 “L” Input Current, CB = 0 V
Shutdown Pin
Input Voltage
SHD “H” Voltage Threshold
SHD “L” Voltage Threshold
SHD “H” Input Current, SHD = 3.6 V
SHD “L” Input Current, SHD = 0 V
Feedback Pin
Input Voltage
Input Current, Vfb = 1.5 V
Sync PWM Mode Characteristics
Switching P−FET Current Limit
Minimum On Time
Rdson Switching P−FET and N_FET
Switching P−FET and N−FET Leakage Current
Output Overvoltage Threshold
I lim
Ton min
Rdson
Ileak
Vo
−
−
−
−
−
800
75
0.23
0
5.0
−
−
−
1.0
−
mA
nsec
W
mA
%
Vfb
Ifb
−0.3
−
−
5.0
Vcc + 0.3
7.5
V
mA
Vshd
Vshd h
Vshd l
Ishd h
Ishd l
−0.3
−
400
−
−0.5
−
920
830
2.2
−
Vcc + 0.3
1200
−
−
−
V
mV
mV
mA
mA
Vcb
Vcb h
Vcb l
Icb0 h
Icb0 l
Icb1 h
Icb1 l
−0.3
−
400
−
−0.5
−
−
−
920
830
2.2
−
0.3
−2.2
Vcc + 0.3
1200
−
−
−
1.0
−
V
mV
mV
mA
mA
mA
mA
Vsync
Fsync
Dcsync Min
Dcsync Max
Vsynch
Vsyncl
Isynch
Isyncl
−0.3
500
−
−
−
400
−
−0.5
−
600
30
70
920
830
2.2
−
Vcc + 0.3
1000
−
−
1200
−
−
−
V
kHz
%
%
mV
mV
mA
mA
Iq PWM
Iq PWM
Iq Pulsed
Iq Off
Vin
−
−
−
−
2.5
175
185
14
0.1
−
−
−
−
0.5
5.2
mA
mA
mA
mA
V
Symbol
Min
Typ
Max
Unit
3. Recommended maximum input voltage is 5 V when the device frequency is synchronized with an external clock signal.
http://onsemi.com
4
NCP1511
ELECTRICAL CHARACTERISTICS (continued)
(V
in
= 3.6 V, Vo = 1.5 V, T
A
= 25°C, Fsyn = 600 kHz 50% Duty Cycle square wave
for PWM mode; T
A
= –30 to 85°C for Min/Max values, unless otherwise noted.
Characteristic
Sync PWM Mode Characteristics (continued)
Feedback Voltage Accuracy, V
out
Set = 1.0 V CB0 = L, CB1 = L
Feedback Voltage Accuracy, V
out
Set = 1.3 V CB0 = L, CB1 = H
Feedback Voltage Accuracy, V
out
Set = 1.5 V CB0 = H, CB1 = H
Feedback Voltage Accuracy, V
out
Set = 1.89 V CB0 = H CB1 = L
Load Transient Response
10 to 100 mA Load Step
Line Transient Response, I
out
= 100 mA
3.0 to 3.6 Vin Line Step
PWM Mode with Internal Oscillator Characteristics
Switching P−FET Current Limit
Minimum On Time
Internal Oscillator Frequency
Rdson Switching P−FET and N_FET
Switching P−FET and N−FET Leakage Current
Output Overvoltage Threshold
Feedback Voltage Accuracy, V
out
Set = 1.0 V CB0 = L, CB1 = L
Feedback Voltage Accuracy, V
out
Set = 1.3 V CB0 = L, CB1 = H
Feedback Voltage Accuracy, V
out
Set = 1.5 V CB0 = H, CB1 = H
Feedback Voltage Accuracy, V
out
Set = 1.89 V CB0 = H CB1 = L
Load Transient Response
10 to 100 mA Load Step
Line Transient Response, I
out
= 100 mA
3.0 to 3.6 Vin Line Step
Pulsed Mode Characteristics
On Time
Output Ripple Voltage, I
out
= 100
mA
Feedback Voltage Accuracy, V
out
Set = 1.0 V CB0 = L, CB1 = L
Feedback Voltage Accuracy, V
out
Set = 1.3 V CB0 = L, CB1 = H
Feedback Voltage Accuracy, V
out
Set = 1.5 V CB0 = H, CB1 = H
Feedback Voltage Accuracy, V
out
Set = 1.89 V CB0 = H CB1 = L
Ton
V
out
V
out
V
out
V
out
V
out
−
−
0.930
1.241
1.430
1.813
660
22
1.000
1.300
1.500
1.890
−
−
1.070
1.359
1.570
1.967
nsec
mV
V
V
V
V
I lim
Ton min
Fosc
Rdson
Ileak
Vo
V
out
V
out
V
out
V
out
V
out
V
out
−
−
700
−
−
−
0.950
1.261
1.450
1.833
−
−
800
75
900
0.23
0
5.0
1.000
1.300
1.500
1.890
35
"10
−
−
1200
−
1.0
−
1.050
1.339
1.550
1.947
−
−
mA
nsec
kHz
W
mA
%
V
V
V
V
mV
mVpp
V
out
V
out
V
out
V
out
V
out
V
out
0.950
1.261
1.450
1.833
−
−
1.000
1.300
1.500
1.890
35
"10
1.050
1.339
1.550
1.947
−
−
V
V
V
V
mV
mVpp
Symbol
Min
Typ
Max
Unit
http://onsemi.com
5
嵌入式系统
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
