Semiconductor Components Industries, LLC, 2005
July, 2005 - Rev. 3
1
Publication Order Number:
NCP5661/D
NCP5661
Low Output Voltage,
Ultra-Fast 1.0 A Low Dropout
Linear Regulator with Enable
The NCP5661 is a high performance, low dropout linear regulator
designed for high power applications that require up to 1.0 A current.
It is offered in both fixed and adjustable output versions. With output
voltages as low as 0.9 V and ultra-fast response times for load
transients, the NCP5661 also provides additional features such as
Enable and Error Flag (for the fixed output version), increasing the
utility of this device. A thermally robust, 5 pin DPAK, combined with
an architecture that offers low ground current (independent of load),
provides for a superior high-current LDO solution.
Features
Ultra-Fast Transient Response (Settling Time: 1-3
ms)
Low Noise Without Bypass Capacitor (26
mV
rms)
Low Ground Current Independent of Load (3.0 mA Maximum)
Fixed/Adjustable Output Voltage Versions
Enable Function
Error Flag (Fixed Output Version)
Current Limit Protection
Thermal Protection
0.9 V Reference Voltage for Ultra-Low Output Operation
Power Supply Rejection Ratio > 65 dB
These are Pb-Free Devices
Applications
Servers
ASIC Power Supplies
Post Regulation for Power Supplies
Constant Current Source
Networking Equipment
Gaming and STB Modules
DPAK-5
CENTER LEAD CROP
CASE 175AA
1
5
MARKING
DIAGRAM
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MARKING
DIAGRAM
See detailed ordering and shipping information in the package
dimensions section on page 10 of this data sheet.
ORDERING INFORMATION
661xG
ALYWW
x
= A for Adjustable Version
B for Fixed 1.2 V
C for Fixed 3.3 V
A
= Assembly Location
L
= Wafer Lot
Y
= Year
WW = Work Week
G
= Pb-Free
Tab = Ground
Pin:
1. Enable
2. V
in
3. Ground
4. V
out
5. Adj (Adjustable Output)
5. Error Flag (Fixed Output)
NCP5661
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2
PIN FUNCTION DESCRIPTION
Pin
Adj/Fixed
Pin Name
Description
1
Enable
This pin allows for on/off control of the regulator. To disable the device, connect to Ground. If this
function is not in use, connect to V
in
.
2
V
in
Positive Power Supply Input Voltage
3
Ground
Power Supply Ground
4
V
out
Regulated Output Voltage
5
Adj
(Adjustable Version)
This pin is connected to the resistor divider network and programs the output voltage.
5
Error Flag
(Fixed Version)
An Error Flag is triggered when the output voltage is out of regulation excluding transient signals
that may occur. Requires a pullup resistor
f
100 k
W
.
MAXIMUM RATINGS
Rating
Symbol
Value
Unit
Input Voltage
V
in
18
V
Output Pin Voltage
V
out
-0.3 to Vin +0.3
V
Adjust Pin Voltage
V
adj
-0.3 to Vin +0.3
V
Enable Pin Voltage
V
en
-0.3 to Vin +0.3
V
Error Flag Voltage
V
ef
-0.3 to Vin +0.3
V
Error Flag Current
I
ef
3.0
mA
Thermal Characteristics
Thermal Resistance, Junction-to-Air
Thermal Resistance, Junction-to-Case
R
JA
R
JC
100
8.0
C/W
Operating Junction Temperature Range
T
J
-40 to +150
C
Storage Temperature Range
T
stg
-55 to +150
C
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.
NOTE:
This device series contains ESD protection and exceeds the following tests:
Human Body Model (HBM) JESD 22-A114-B
Machine Model (MM) JESD 22-A115-A.
The maximum package power dissipation is:
P
D
+
T
J(max)
*
T
A
R
q
JA
The bipolar process employed for this IC is fully characterized and rated for reliable 18 V V
CCmax
operation. To avoid damaging
the part or degrading it's reliability, power dissipation transients should be limited to under 20 W for DPAK.
For open-circuit to short-circuit transient,
P
DTransient
= V
CCmax
* I
SC
.
NCP5661
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3
ELECTRICAL CHARACTERISTICS
(V
in
- V
out
= 1.5 V, for typical values T
J
= 25
C, for min/max values T
J
= -40
C to 125
C, C
in
= C
out
= 150
m
F unless otherwise noted.)
Characteristic
Symbol
Min
Typ
Max
Unit
ADJUSTABLE OUTPUT VERSION
Input Voltage
V
in
2.0
-
9.0
V
Output Noise Voltage
V
n
-
26
-
m
V
rms
Output Voltage Accuracy
T
J
= 25
C (I
out
= 10 mA to 1.0 A)
T
J
= -20 to +125
C (I
out
= 10 mA to 1.0 A)
T
J
= -40 to +150
C (I
out
= 10 mA to 1.0 A)
V
out
-1%
-1.5%
-2%
-
0.9
-
+1%
+1.5%
+2%
V
Adjustable Pin Input Current
I
adj
-
40
-
nA
Line Regulation (I
out
= 10 mA, V
out
+1.5 V < V
in
< 7.0 V)
REG
line
-
0.03
-
%
Load Regulation (10 mA < I
out
< 1.0 A)
REG
load
-
0.03
-
%
Dropout Voltage (I
out
= 1.0 A)
V
DO
-
1.0
1.3
V
Peak Output Current Limit
I
out
1.0
-
-
A
Internal Current Limitation
I
lim
-
1.5
-
A
Ripple Rejection (120 Hz)
Ripple Rejection (1.0 kHz)
RR
-
-
70
65
-
-
dB
Thermal Shutdown (Guaranteed by Design)
T
SHD
-
160
-
C
Ground Current
I
out
= 1.0 A
Disabled State
I
q
I
qds
-
-
1.3
10
3.0
300
mA
m
A
Enable Input Threshold Voltage
Voltage Increasing, On State, Logic High
Voltage Decreasing, Off State, Logic Low
V
en
1.3
-
-
-
-
0.3
V
Enable Input Current
Enable Pin Voltage = 0.3 V
max
Enable Pin Voltage = 1.3 V
min
I
en
-
-
0.5
0.5
-
-
m
A
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4
ELECTRICAL CHARACTERISTICS
(V
in
- V
out
= 1.5 V, for typical values T
J
= 25
C, for min/max values T
J
= -40
C to 125
C, C
in
= C
out
= 150
m
F unless otherwise noted.)
Characteristic
Symbol
Min
Typ
Max
Unit
FIXED OUTPUT VOLTAGE
Input Voltage
V
in
2.0
-
9.0
V
Output Noise Voltage (V
out
= 0.9 V)
V
n
-
26
-
m
V
rms
Output Voltage Accuracy (Note 1)
T
J
= 25
C (I
out
= 10 mA to 1.0 A)
T
J
= -20 to +125
C (I
out
= 10 mA to 1.0 A)
T
J
= -40 to +150
C (I
out
= 10 mA to 1.0 A)
V
out
-1%
-1.5%
-2%
-
V
out
-
+1%
+1.5%
+2%
V
Line Regulation (I
out
= 10 mA, V
out
+1.5 V < V
in
< 7.0 V)
REG
line
-
0.03
-
%
Load Regulation (10 mA < I
out
< 1.0 A)
REG
load
-
0.2
-
%
Dropout Voltage (I
out
= 1.0 A)
V
DO
-
1.0
1.3
V
Peak Output Current Limit
I
out
1.0
-
-
A
Internal Current Limitation
I
lim
-
1.5
-
A
Ripple Rejection (120 Hz)
Ripple Rejection (1.0 kHz)
RR
-
-
70
65
-
-
dB
Thermal Shutdown (Guaranteed by Design)
T
SHD
-
160
-
C
Ground Current
I
out
= 1.0 A
Disabled State
I
q
I
qds
-
-
1.3
30
3.0
300
mA
m
A
Enable Input Threshold Voltage
Voltage Increasing, On State, Logic High
Voltage Decreasing, Off State, Logic Low
V
en
1.3
-
-
-
-
0.3
V
Enable Input Current
Enable Pin Voltage = 0.3 V
max
Enable Pin Voltage = 1.3 V
min
I
en
-
-
0.5
0.5
-
-
m
A
Error Flag (Fixed Output)
1.2 V Output
3.3 V Output
V
eflt
88
90
92
94
97
97
% of V
out
Error Flag Output Low Voltage Saturation (I
ef
= 1.0 mA)
V
efdo
-
200
-
mV
Error Flag Leakage
I
efleak
-
1.0
-
m
A
Error Flag Blanking Time (Note 2)
T
ef
-
50
-
m
s
1. Fixed output voltages available at 0.9 V, 1.2 V, 1.5 V, 1.8 V, 2.5 V, 3.0 V, 3.3 V per request.
2. Can be disabled per customer request.
NCP5661
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5
Figure 1. Typical Schematic, Adjustable Output Version
Voltage
Reference
Block
V
ref
= 0.9 V
Output
Stage
C
in
R1
R2
V
out
ADJ
GND
IN
GND
Figure 2. Typical Schematic, Fixed Output Version
Enable
Block
R3
R4
EN
ON
OFF
Voltage
Reference
Block
V
ref
= 0.9 V
Output
Stage
R1
R2
V
out
GND
IN
Cc
GND
Enable
Block
R3
R4
EN
ON
OFF
Rflag = 100 k
W
Error
Flag
EF
R1
+
R2
Vout
Vref
*
1
C
C
*
V
in
C
in
C
out
V
in
C
out
*C
C
= 5.0 to 200 pF
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6
0.70
0.75
0.80
0.85
0.90
0.95
1.00
0.0
0.1
I
out
, OUTPUT CURRENT (A)
V
DO
, DROPOUT VOL
T
AGE
(V)
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
V
out
= 2.5 V Adjustable
C
in
= 150
m
F
C
out
= 10 to 150
m
F
T
J
= 25
C
1.2
1.0
0.8
0.6
0.4
0.2
0
-40
-20
0
20
40
60
80
100
120
140
V
DO
, DROPOUT VOL
T
AGE
(V)
T
J
, JUNCTION TEMPERATURE (
C)
T
J
, JUNCTION TEMPERATURE (
C)
I
GND
, GROUND CURRENT (mA)
0
-40
-20
0
20
40
60
80
100
120
140
3.5
3.0
2.5
2.0
1.5
1.0
0.5
T
J
, JUNCTION TEMPERATURE (
C)
-40
-20
0
20
40
60
80
100
120
140
2.0
1.8
1.6
1.4
1.2
1.0
I
SC
, SHOR
T CIRCUIT LIMIT (A)
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
V
in
, INPUT VOLTAGE (V)
V
out
, OUTPUT VOL
T
AGE (V)
0.95
0.90
0.85
0.80
0.75
0.70
I
out
= 10 mA
C
in
= 150
m
F
C
out
= 1.0 to 150
m
F
T
J
= 25
C
I
out
, OUTPUT CURRENT (A)
V
out
, OUTPUT VOL
T
AGE (V)
V
in
= 3.3 V
I
out
= 1.0 A maximum
C
in
= 150
m
F
C
out
= 1.0 to 150
m
F
T
J
= 25
C
0.0
0.2
0.4
0.6
0.8
1.0
0.900
0.898
0.896
0.894
0.892
0.890
Figure 3. Dropout Voltage vs. Temperature
Figure 4. Dropout Voltage vs. Output Current
Figure 5. Ground Current vs. Temperature
Figure 6. Short Circuit Current Limit vs.
Temperature
Figure 7. Output Voltage vs. Input Voltage
Figure 8. Output Voltage vs. Output Load Current
NCP5661
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7
20
16
10
2
0
Figure 9. Output Current vs. Input-Output
Voltage Differential
Figure 10. Ripple Rejection vs. Frequency
100
90
80
70
60
50
40
30
20
10
0
NOISE
DENSITY (nV
rms
/
Hz
)
V
in
= 3.3 V
V
out
= 0.9 V
I
out
= 10 mA
C
in
= 150
m
F
C
out
= 150
m
F
T
J
= 25
C
F, FREQUENCY (kHz)
Start: 100 Hz
Stop: 100 kHz
100
90
80
70
60
50
40
30
20
10
0
NOISE DENSITY (nV
rms
/
Hz
)
V
in
= 3.3 V
V
out
= 0.9 V
I
out
= 1.0 A
C
in
= 150
m
F
C
out
= 150
m
F
T
J
= 25
C
F, FREQUENCY (kHz)
Start: 100 Hz
Stop: 100 kHz
Figure 11. Noise Density vs. Frequency
OUTPUT
CURRENT (A)
INPUT-OUTPUT VOLTAGE DIFFERENTIAL (V)
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
T
A
= 25
C
L = 25 mm Copper
Figure 12. Noise Density vs. Frequency
1000
100
10
1
0
RR, RIPPLE REJECTION (dB)
F, FREQUENCY (kHz)
90
80
70
60
50
40
30
20
10
0
V
in
= 4.0 V
V
out
= 0.9 V
C
in
= 0
m
F
C
out
= 1.0
m
F
T
J
= 25
C
I
out
= 10 mA
I
out
= 1.0 A
14
12
4
6
8
1000
100
10
1.0
0.10
0.01
ESR (
W
)
Unstable
OUTPUT CURRENT (mA)
100
1000
Figure 13. 1.2 Volt Output Stability with Output
Capacitor ESR
Figure 14. 3.3 Volt Output Stability with Output
Capacitor ESR
0
200 300 400 500 600 700 800 900
150
m
F
Stable
10
m
F
100
m
F
1000
100
10
1.0
0.10
0.01
ESR (
W
)
Unstable
OUTPUT CURRENT (mA)
100
1000
0
200 300 400 500 600 700 800 900
Stable
150
m
F
10
m
F
100
m
F
NCP5661
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8
V
in
= 4.0 V
V
out
= 0.9 V
C
in
= 150
m
F
C
out
= 150
m
F
T
J
= 25
C
I
out
= 10 mA to 1.0 A
I
out
0.5 A/Div
V
out
10 mV/Div
TIME (1.0
m
s/Div)
I
out
0.5 A/Div
V
out
10 mV/Div
TIME (1.0
m
s/Div)
V
in
= 4.0 V
V
out
= 0.9 V
C
in
= 150
m
F
C
out
= 150
m
F
T
J
= 25
C
I
out
= 1.0 A to 10 mA
Figure 15. Load Transient Response
Figure 16. Load Transient Response
APPLICATION INFORMATION
The NCP5661 is a high performance low dropout 1.0 A
linear regulator suitable for high power applications,
featuring an ultra-fast response time and low noise without
a bypass capacitor. It is offered in both fixed and adjustable
output versions with voltages as low as 0.9 V. Additional
features, such as Enable and Error Flag (fixed output
version) increase the utility of the NCP5661. It is thermally
robust and includes the safety features necessary during a
fault condition, which provide for an attractive high current
LDO solution for server, ASIC power supplies, networking
equipment applications, and many others.
Input Capacitor
The recommended input capacitor value is a 150
mF
OSCON with an Equivalent Series Resistance (ESR) of
50 m
W. It is especially required if the power source is
located more than a few inches from the NCP5661. This
capacitor will reduce device sensitivity and enhance the
output transient response time. The PCB layout is very
important and in order to obtain the optimal solution, the Vin
and GND traces should be sufficiently wide to minimize
noise and unstable operation.
Output Capacitor
Proper output capacitor selection is required to maintain
stability. The NCP5661 is guaranteed to be stable at an
output capacitance of, C
out
> 10
mF with an ESR < 300 mW
over the output current range of 10 mA to 1.0 A. For PCB
layout considerations, place the recommended ceramic
capacitor close to the output pin and keep the leads short.
This should help ensure ultra-fast transient response times.
Adjustable Output Operation
The application circuit for the adjustable output version is
shown in Figure 1. The reference voltage is 0.9 V and the
adjustable pin current is typically 40 nA. A resistor divider
network, R1 and R2, is calculated using the following
formula:
R1
+
R2
Vout
Vref
*
1
Current Limit Operation
As the peak output current increases beyond its limitation,
the device is internally clampled to 1.5 A, thus causing the
output voltage to decrease and go out of regulation. This
allows the device never to exceed the maximum power
dissipation.
Error Flag Operation
The Error Flag pin on the NCP5661 will produce a logic
Low when it drops below the nominal output voltage. Refer
to the electrical characteristics for the threshold values at
which point the Error Flag goes Low. When the NCP5661
is above the nominal output voltage, the Error Flag will
remain at logic High.
The external pullup resistor needs to be connected
between V
in
(Pin 1) and the Error Flag pin (Pin 5). A resistor
of approximately 100 k
W is recommended to minimize the
current consumption. No pullup resistor is required if the
Error Flag output is not being used.
NCP5661
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9
Figure 17. Test Board used for Evaluation
NCP5661 Evaluation Board
NCP5661
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10
ORDERING INFORMATION
Device
Nominal Output Voltage
Package
Shipping
NCP5661DTADJRKG
Adj
(Pb-Free)
DPAK
2500 Tape & Reel
NCP5661DT12RKG (Note 3)
Fixed, 1.2 V
(Pb-Free)
2500 Tape & Reel
NCP5661DT33RKG (Note 3)
Fixed, 3.3 V
(Pb-Free)
2500 Tape & Reel
3. Fixed output voltages available at 0.9 V, 1.5 V, 1.8 V, 2.5 V, 3.0 V per request.
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.
NCP5661
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11
PACKAGE DIMENSIONS
DPAK-5
CENTER LEAD CROP
CASE 175AA-01
ISSUE A
D
A
K
B
R
V
S
F
L
G
5 PL
M
0.13 (0.005)
T
E
C
U
J
H
-T-
SEATING
PLANE
Z
DIM
MIN
MAX
MIN
MAX
MILLIMETERS
INCHES
A
0.235
0.245
5.97
6.22
B
0.250
0.265
6.35
6.73
C
0.086
0.094
2.19
2.38
D
0.020
0.028
0.51
0.71
E
0.018
0.023
0.46
0.58
F
0.024
0.032
0.61
0.81
G
0.180 BSC
4.56 BSC
H
0.034
0.040
0.87
1.01
J
0.018
0.023
0.46
0.58
K
0.102
0.114
2.60
2.89
L
0.045 BSC
1.14 BSC
R
0.170
0.190
4.32
4.83
S
0.025
0.040
0.63
1.01
U
0.020
---
0.51
---
V
0.035
0.050
0.89
1.27
Z
0.155
0.170
3.93
4.32
NOTES:
1. DIMENSIONING AND TOLERANCING
PER ANSI Y14.5M, 1982.
2. CONTROLLING DIMENSION: INCH.
R1
0.185
0.210
4.70
5.33
R1
1 2 3 4 5
6.4
0.252
0.8
0.031
10.6
0.417
5.8
0.228
SCALE 4:1
mm
inches
0.34
0.013
5.36
0.217
2.2
0.086
SOLDERING FOOTPRINT*
*For additional information on our Pb-Free strategy
and soldering details, please download the
ON Semiconductor Soldering and Mounting
Techniques Reference Manual, SOLDERRM/D.
NCP5661
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12
ON Semiconductor and are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice
to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any liability
arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages.
"Typical" parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All
operating parameters, including "Typicals" must be validated for each customer application by customer's technical experts. SCILLC does not convey any license under its patent rights
nor the rights of others. SCILLC products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications
intended to support or sustain life, or for any other application in which the failure of the SCILLC product could create a situation where personal injury or death may occur. Should
Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and its officers, employees, subsidiaries, affiliates,
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associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was negligent regarding the design or manufacture of the part. SCILLC is an Equal
Opportunity/Affirmative Action Employer. This literature is subject to all applicable copyright laws and is not for resale in any manner.
PUBLICATION ORDERING INFORMATION
N. American Technical Support: 800-282-9855 Toll Free
USA/Canada
Japan: ON Semiconductor, Japan Customer Focus Center
2-9-1 Kamimeguro, Meguro-ku, Tokyo, Japan 153-0051
Phone: 81-3-5773-3850
NCP5661/D
The product described herein (NCP5661), may be covered by one or more of the following U.S. patents: 5,920,184; 5,834,926. There
may be other patents pending.
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