AP7168

AP7168
1.2A LOW DROPOUT REGULATOR WITH POK
Description
Pin Assignments
NEW PRODUCT
The AP7168 is a 1.2A, adjustable output voltage, ultra-low
dropout linear regulator. The device includes pass element,
error amplifier, band-gap reference, current limit and thermal
shutdown circuitry. The device is turned on when EN pin is
set to logic high level. A Power-OK (POK) output is available
for power sequence control.
( Top View )
The characteristics of the low dropout voltage and low
quiescent current make it suitable for low to medium power
applications, for example, laptop computers, audio and video
applications, and battery powered devices. The typical
quiescent current is approximately 125µA.
IN
1
8
OUT
POK
2
7
FB
NC
3
6
NC
EN
4
5
GND
Built-in current-limit and thermal-shutdown functions prevent
IC from damage in fault conditions. The AP7168 is available
in SO-8EP package.
SO-8EP
Features
Applications
•
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Wide input voltage range: 2.2V – 5.5V
230mV very low dropout at 500mA load
500mV very low dropout at 1A load
Very low quiescent current (IQ): 125µA typical
Adjustable output voltage range: 0.8V to 5.0V
Very fast transient response
High PSRR
Accurate voltage regulation
Current limiting and short circuit protection
Thermal shutdown protection
Stable with any type output capacitor ≥ 4.7µF
Ambient temperature range -40ºC to 85°C
SO-8EP: Available in “Green” Molding Compound (No
Br, Sb)
Lead Free Finish/ RoHS Compliant (Note 1)
Notes:
Servers and laptops
Smart phone and PDA
MP3/MP4
Bluetooth headset
Low and medium power applications
FPGA and DSP core or I/O power
1. EU Directive 2002/95/EC (RoHS). All applicable RoHS exemptions applied. Please visit our website at
http://www.diodes.com/products/lead_free.html.
Typical Application Circuit
VIN
VOUT
IN
OUT
100kOhm
R1
AP7168
1µF
POK
10µF
FB
R2
Enable
EN
GND
⎛ R ⎞
VOUT = VREF ⎜⎜1 + 1 ⎟⎟
⎝ R2 ⎠
AP7168
Document number: DS32019 Rev. 2 - 2
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AP7168
1.2A LOW DROPOUT REGULATOR WITH POK
NEW PRODUCT
Pin Descriptions
Name
IN
POK
EN
GND
FB
Pin Number
1
2
4
5
7
OUT
8
NC
3, 6
Description
Voltage input pins, to be tied together externally. Bypass to ground through at least 1µF capacitor.
Power-OK output, active-high open-drain.
Enable input, active high.
Ground.
Output feedback.
Voltage output pins, to be tied together externally. Bypass to ground through at least 4.7µF
ceramic capacitor.
No connection.
Functional Block Diagram
IN
OUT
Gate
Driver
EN
Current Limit
and Thermal
Shutdown
FB
0.8V
POK
0.744V
GND
Absolute Maximum Ratings
Symbol
ESD HBM
ESD MM
VIN
TJ
TST
PD
Notes:
Parameter
Human Body Model ESD Protection
Machine Model ESD Protection
Input Voltage
OUT, FB, POK, EN Voltage
Continuous Load Current
Operating Junction Temperature Range
Storage Temperature Range
Power Dissipation
SO-8EP (Note 2, 4)
Ratings
4
300
7
VIN + 0.3
Internal Limited
-40 ~ 150
-65 ~150
4.0
Unit
KV
V
V
V
°C
°C
W
2. Ratings apply to ambient temperature at 25°C
Recommended Operating Conditions
Symbol
VIN
IOUT
TA
Parameter
Input voltage
Output Current
Operating Ambient Temperature
AP7168
Document number: DS32019 Rev. 2 - 2
2 of 11
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Min
Max
Unit
2.2
0
-40
5.5
1.2
85
V
A
°C
September 2010
© Diodes Incorporated
AP7168
1.2A LOW DROPOUT REGULATOR WITH POK
Electrical Characteristics
o
(TA = 25 C, VIN = VOUT +1V, CIN = 1μF, COUT = 1μF, VEN = 2V, unless otherwise stated)
Symbol
Parameter
Test Conditions
IQ
ISHDN
NEW PRODUCT
VDropout
VREF
IFB
VOUT
ΔVOUT
/ VOUT
ΔVIN
ΔVOUT / VOUT
tST
Input Quiescent Current
Input Shutdown Current
Dropout Voltage
FB reference voltage
FB leakage
Output Voltage Total Accuracy
Line Regulation
Load Regulation
Start-up Time, from EN high to POK
high
PSRR
Power Supply Rejection Ratio
ILIMIT
ISHORT
VIL
VIH
IEN
VOL
Current limit
Short-circuit Current
EN Input Logic Low Voltage
EN Input Logic High Voltage
EN Input leakage
POK output low voltage
VPOK_TH_UP
VPOK_Hys
POK deglitch
IPOK_LK
TSHDN
THYS
θJA
Notes:
IOUT= 0
VEN = 0V, IOUT = 0 (Note 3)
VOUT ≥ 1.5V, IOUT = 0.5A
VOUT ≥ 1.5V, IOUT = 1A
Min
Typ.
Max
Unit
⎯
-1
125
0.1
230
500
0.8
0.01
180
1
µA
µA
mV
mV
V
µA
%
⎯
-3
VIN = VOUT +1V to 5.5V,
IOUT = 1mA
IOUT from 1mA to 1A
VEN = 0V to 2.0V, IOUT = 100mA,
VIN = 3.3V
1kHz, VIN = 3.3V, VOUT = 1.2V,
IOUT = 100mA
VOUT = 1.8V, ROUT = 0.5Ω
VIN = 3.3V, VOUT < 0.2V
800
1
3
0.02
-1.5
1.2
%/V
1.5
%
190
µs
60
dB
1.6
750
0.01
100
1
200
A
mA
V
V
µA
mV
87%
92%
97%
Vref
⎯
4%
160
0.01
145
25
1
Vref
µs
µA
°C
°C
0.4
VEN = 0V or 5.5V
Force 2mA
FB (or OUT for fixed version)
Output voltage (rising) POK threshold
rising
Output voltage POK hysteresis
VIN = 3.3V, VOUT = 1.2V
POK leakage current
VPOK = 5.5V
Thermal shutdown threshold
Thermal shutdown hysteresis
Thermal Resistance Junction-toSOP-8L-EP (Note 4)
Ambient
1.4
⎯
27
o
C/W
3. POK pin must be disconnected from IN pin.
4. Test condition for SO-8EP: Device mounted on 2" x 2" FR-4 substrate PCB, 2oz copper, with minimum recommended pad on top
layer and thermal vias to bottom layer ground plane.
AP7168
Document number: DS32019 Rev. 2 - 2
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© Diodes Incorporated
AP7168
1.2A LOW DROPOUT REGULATOR WITH POK
Typical Performance Characteristics
Output Voltage vs. Temperature
Output Voltage vs. Tem perature
3.40
1.30
Output Voltage (V)
Output Voltage (V)
VOUT = 1.2V
3.35
3.30
3.25
1.25
1.20
1.15
1.10
3.20
-50
-25
0
25
50
75
100
-50
125
-25
0
Quiescent Current vs. Input Voltage
155
140
125
110
95
Iout=0mA
Iout=500mA
Quiescent Current ( μ A)
Quiescent Current (μA)
50
75
100
125
Quiescent Current vs. IOUT
VOUT=3.3V
170
25
Tem perature ( 0C)
0
Temperature ( C)
80
VOUT=1.8V
170
160
150
140
130
120
110
VIN=2.5V
VIN=3.3V
100
4.0
4.3
4.6
4.9
5.2
5.5
0.0
0.2
0.4
0.6
Input Voltage (V)
0.8
1.0
1.2
IOUT (A)
Reference Voltage vs. Temperature
Quiescent Current vs. Tem perature
0.810
155
140
125
110
VIN=2.2V, Vout=1.0V
95
VIN=3.3V, Vout=1.8V
Reference Voltage (V)
170
Quiescent Current ( π A)
NEW PRODUCT
VOUT = 3.3V
0.805
0.800
0.795
Vin=2.2V
Vin=3.3V
Vin=5.5V
VIN=5.0V, Vout=3.3V
0.790
80
-50.0
-25.0
0.0
25.0
50.0
75.0
100.0
125.0
Document number: DS32019 Rev. 2 - 2
-25
0
25
50
75
100
125
0
Temperature ( C)
Tem perature ( 0C)
AP7168
-50
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AP7168
1.2A LOW DROPOUT REGULATOR WITH POK
Typical Performance Characteristics (Continued)
Line Regulation
Load Regulation
VOUT=1.8V, IOUT=1mA
VIN=2.2V, VOUT=1.2V,
0.10
0.5
Change in V OUT (%)
Change in V OUT (%/V)
0.05
0.00
-0.05
25°C
85°C
85°C
0.3
-40°C
0.2
0.1
0.0
-0.1
-0.2
-0.3
-0.4
-40°C
-0.10
-0.5
3.0
3.5
4.0
4.5
5.0
5.5
0.0
0.4
0.8
V IN (V)
Short Circuit Current vs. Temperature
VOUT=1.2V
VOUT=1.2V
0.80
Short Circuit Current (A)
Short Circuit Current (A)
0.77
1.2
IOUT (A)
Short Circuit Current vs. Input Voltage
0.76
0.75
0.74
0.73
0.72
0.71
0.70
0.75
0.70
0.65
0.69
2.2
2.4
2.6
2.8
3
3.2
0.60
3.4
-50
Input Voltage (V)
-25
0
25
50
75
o
Temperature ( C)
Dropout Voltage vs. IOUT
PSRR
VOUT=3.3V
700
-40
600
-45
-50
500
PS RR (dB)
Dropout Voltage (mV)
NEW PRODUCT
25°C
0.4
400
300
-55
-60
-65
-70
200
25°C
100
-75
85°C
-40°C
0
0
0.2
0.4
0.6
0.8
1
1.2
-80
100
IOUT(A)
AP7168
Document number: DS32019 Rev. 2 - 2
5 of 11
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1000
10000
Frequency (Hz)
100000
September 2010
© Diodes Incorporated
AP7168
1.2A LOW DROPOUT REGULATOR WITH POK
Typical Performance Characteristics (Continued)
NEW PRODUCT
Line Transient Response
Line Transient Response
VIN =3V to 5.5V
VIN =5.5V to 3V
COUT =10uF
(Ceramic)
COUT =10uF
(Ceramic)
VIN
2V/div
VIN
2V/div
VOUT
50mV/div
VOUT
50mV/div
Time (5ms/div)
Time (500us/div)
Output Load Transient Response (VOUT=1.8V)
Output Load Transient Response (VOUT=3.3V)
COUT=470uF (electrolytic)
VOUT
COUT=10uF (Ceramic)
100mV/div
COUT=470uF (electrolytic)
VOUT
COUT=10uF (Ceramic)
100mV/div
COUT=1uF (Ceramic)
COUT=1uF (Ceramic)
1.2A
IOU
1.2A
1A/us
500mA/div
IOU
1A/us
500mA/div
50mA
50mA
Time (100us/div)
Time (100us/div)
Start-up Time (VOUT=1.2V, IOUT=0.1A)
Start-up Time (VOUT=1.2V, IOUT=1.2A)
VEN
2V/div
VEN
2V/div
COUT=10uF
COUT=10uF
VOUT
1V/div
VOUT
1V/div
VPOK
2V/div
VPOK
2V/div
Time (50us/div)
AP7168
Document number: DS32019 Rev. 2 - 2
Time (50us/div)
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AP7168
1.2A LOW DROPOUT REGULATOR WITH POK
Typical Performance Characteristics (Continued)
Current Limit vs. Temperature
NEW PRODUCT
Current Limit (A)
1.8
1.7
1.6
1.5
VIN =2.8V,Vout=1.8V
VIN =3.3V,Vout=1.8V
1.4
-50
-25
0
25
50
75
100
o
Temperature ( C)
Application Note
Input Capacitor
A 1μF ceramic capacitor is recommended to connect
between IN and GND pins to decouple input power supply
glitch and noise. The amount of the capacitance may be
increased without limit. A lower ESR (Equivalent Series
Resistance) capacitor allows the use of less capacitance,
while higher ESR type requires more capacitance. This
input capacitor should be located as close as possible to
the device to assure input stability and less noise. For
PCB layout, a wide copper trace is required for both IN
and GND.
VIN
VOUT
IN
CIN
OUT
100kOhm
POK
COUT
R1
AP7168
FB
R2
Enable
EN
GND
Output Capacitor
The output capacitor is required to stabilize and help the
transient response of the LDO. The AP7168 is designed to
have excellent transient response for most applications
with a small amount of output capacitance. The AP7168 is
stable for all available types and values of output
capacitors ≥ 4.7μF. The device is also stable with multiple
capacitors in parallel, which can be of any type of value.
Additional capacitance helps to reduce undershoot and
overshoot during transient. This capacitor should be
placed as close as possible to OUT and GND pins for
optimum performance.
The output voltage is calculated by:
⎛
R ⎞
VOUT = VREF ⎜⎜1 + 1 ⎟⎟
R2 ⎠
⎝
Where VREF=0.8V (the internal reference voltage)
Rearranging the equation will give the following equation
to find the approximate resistor divider values:
⎞
⎛V
R1 = R 2 ⎜⎜ OUT − 1⎟⎟
⎠
⎝ VREF
Adjustable Operation
The AP7168 provides output voltage from 0.8V to 5.0V
through external resistor divider as shown below.
AP7168
Document number: DS32019 Rev. 2 - 2
To maintain the stability of the internal reference voltage,
R2 needs to be kept smaller than 250kΩ.
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AP7168
1.2A LOW DROPOUT REGULATOR WITH POK
NEW PRODUCT
Application Note (Continued)
No Load Stability
Wide Output Range
Other than external resistor divider, no minimum load is
required to keep the device stable. The device will remain
stable and regulated in no load condition.
The AP7168, with a wide output range of 0.8V to 5.0V,
provides a versatile solution for many portable and low
power applications.
ENABLE/SHUTDOWN Operation
Thermal Shutdown Protection
The AP7168 is turned on by setting the EN pin high, and is
turned off by pulling it low. If this feature is not used, the
EN pin should be tied to IN pin to keep the regulator output
on at all time. To ensure proper operation, the signal
source used to drive the EN pin must be able to swing
above and below the specified turn-on/off voltage
thresholds listed in the Electrical Characteristics section
under VIL and VIH.
Thermal protection disables the output when the junction
temperature rises to approximately +145°C, allowing the
device to cool down. When the junction temperature
reduces to approximately +120°C the output circuitry is
enabled again. Depending on power dissipation, thermal
resistance, and ambient temperature, the thermal
protection circuit may cycle on and off. This cycling limits
the heat dissipation of the regulator, protecting it from
damage due to overheating.
POWER-OK
The Power-Ok (POK) pin is an active high open-drain
output. It can be connected to any 5.5V or lower rail
through an external pull-up resistor. The recommended
sink current of POK pin is up to 4mA, so the pull-up
resistor for POK should be in the range of 10kΩ to 1MΩ. If
output voltage monitoring is not needed, the POK pin can
be left floating.
Power Dissipation
The device power dissipation and proper sizing of the
thermal plane that is connected to the thermal pad is
critical to avoid thermal shutdown and ensuring reliable
operation. Power dissipation of the device depends on
input voltage and load conditions and can be calculated
by:
PD = ( VIN − VOUT )xIOUT
Current Limit Protection
When output current at OUT pin is higher than current limit
threshold, the current limit protection will be triggered and
clamp the output current to approximately 1.6A (1.2A min)
to prevent over-current and to protect the regulator from
damage due to overheating.
Short Circuit Protection
When OUT pin is short-circuited to GND or OUT pin
voltage is less than 200mV, short circuit protection will be
triggered and clamp the output current to approximately
750mA. This feature protects the regulator from overcurrent and damage due to overheating.
The AP7168 is available in the SO-8EP packages, both
with exposed pad, which is the primary conduction path for
heat to the printed circuit board (PCB). The pad can be
connected to ground or be left floating; however, to ensure
the device will not overheat, it should be attached to an
appropriate amount of copper PCB area.
However, the maximum power dissipation that can be
handled by the device depends on the maximum junction
to ambient thermal resistance, maximum ambient
temperature, and maximum device junction temperature,
which can be approximated by the equation below:
Low Quiescent Current
The AP7168, consuming only around 150µA for all input
range and output loading, provides great power saving in
portable and low power applications.
AP7168
Document number: DS32019 Rev. 2 - 2
8 of 11
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PD (max@ TA ) =
( +150°C − TA )
R θJA
September 2010
© Diodes Incorporated
AP7168
1.2A LOW DROPOUT REGULATOR WITH POK
Ordering Information
AP7168 - SP G - 13
Package
NEW PRODUCT
SP : SO-8EP
Device
AP7168-SPG-13
Notes:
Package
Code
SP
Green
Packing
G : Green
13 : Tape & Reel
13” Tape and Reel
Quantity
Part Number Suffix
2500/Tape & Reel
-13
Packaging
(Note 5)
SO-8EP
5. Pad layout as shown on Diodes Inc. suggested pad layout document AP02001, which can be found on our website at
http://www.diodes.com/datasheets/ap02001.pdf.
Marking Information
SO-8EP
( Top View )
8
5
Logo
Part No.
AP7168
YY WW X X E
1
AP7168
Document number: DS32019 Rev. 2 - 2
G : Green
YY : Year : 08, 09,10~
WW : Week : 01~52; 52
represents 52 and 53 week
X : Internal Code
SOP-8L-EP
4
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AP7168
1.2A LOW DROPOUT REGULATOR WITH POK
Package Outline Dimensions
Package Type: SO-8EP
Detail "A"
Exposed pad
2.4Ref.
3.70/4.10
45°
NEW PRODUCT
0.35max.
3.85/3.95
5.90/6.10
7°~9°
7°~9° 1
1
0.15/0.25
Bottom View
1.75max.
1.30/1.50
3.3Ref.
0/0.13
0.254
0.3/0.5
1.27typ
4.85/4.95
1
Gauge Plane
Seating Plane
0.62/0.82
Detail "A"
8x-0.60
5.4
Exposed pad
8x-1.55
6x-1.27
Land Pattem Recommendation
(Unit:mm)
Notes:
6. All dimensions are in millimeters. Angles are in degrees.
7. Coplanarity applies to the exposed heat sink slug as well as the terminals.
AP7168
Document number: DS32019 Rev. 2 - 2
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AP7168
1.2A LOW DROPOUT REGULATOR WITH POK
IMPORTANT NOTICE
DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO THIS
DOCUMENT, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION).
NEW PRODUCT
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changes without further notice to this document and any product described herein. Diodes Incorporated does not assume any liability
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LIFE SUPPORT
Diodes Incorporated products are specifically not authorized for use as critical components in life support devices or systems without
the express written approval of the Chief Executive Officer of Diodes Incorporated. As used herein:
A. Life support devices or systems are devices or systems which:
1. are intended to implant into the body, or
2. support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided
in the labeling can be reasonably expected to result in significant injury to the user.
B.
A critical component is any component in a life support device or system whose failure to perform can be reasonably expected
to cause the failure of the life support device or to affect its safety or effectiveness.
Customers represent that they have all necessary expertise in the safety and regulatory ramifications of their life support devices or
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concerning their products and any use of Diodes Incorporated products in such safety-critical, life support devices or systems,
notwithstanding any devices- or systems-related information or support that may be provided by Diodes Incorporated. Further,
Customers must fully indemnify Diodes Incorporated and its representatives against any damages arising out of the use of Diodes
Incorporated products in such safety-critical, life support devices or systems.
Copyright © 2010, Diodes Incorporated
www.diodes.com
AP7168
Document number: DS32019 Rev. 2 - 2
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