AME, Inc.
1
AME8844 750mA CMOS LDO
n Functional Block Diagram
(Fixed Versions)
l Very Low Dropout Voltage
l Guaranteed 750mA Output
l Accurate to within 1.5%
l 45µA Quiescent Current T ypically
l Over-T emperature Shutdown
l Current Limiting
l Short Circuit Current Fold-back
l Noise Reduction Bypass Capacitor (Fixed
Versions)
l Power-Saving Shutdown Mode
l Space-Saving MSOP-8 Package
l 6 Factory Pre-set Output V oltages
l Low T emperature Coefficient
l Adjustable V ersion
l Power Good Output Function.
The AME8844 family of positive, linear regulators fea-
ture low quiescent current (45µA typ.) with low dropout
voltage, making them ideal for battery applications.
Output voltages are set at the factory and trimmed to
1.5% accuracy.
These rugged devices have both Thermal Shutdown,
and Current Fold-back to prevent device failure under the
"Worst" of operating conditions.
An additional feature is a “Power Good” detector , which
pulls low when the output is out of regulation.
The AME8844 is stable with an output capacitance of
4.7µF or greater .
l Instrumentation
l Portable Electronics
l Wireless Devices
l PC Peripherals
l Battery Powered Widgets
n General Description
n Features
n Applications
n Functional Block Diagram
(Adjustable Version)
(external)
(external)
Overcurrent
Shutdown Thermal
Shutdown
AMP
IN
1.242V
GND
OUT
R1
R2
EN
ADJ
GND
OUT
IN
PG
Overcurrent
Shutdown
Thermal
Shutdown
EN
Vref
Vref x85%
Vrefx115% AMP
R2
R1
n T ypical Applications
AME8844 OUT
IN
C3
4.7µ
µµ
µF
C1
1µ
µµ
µF
GND
OUT
EN
PG
IN
5V
AME, Inc.
2
750mA CMOS LDO
AME8844
n Pin Configuration
MSOP-8
Top View
AME 8844AEQAxxx
1. EN
2. VIN
3. PG
4. VOUT
5. GND
6. GND
7. GND
8. GND
Note:
X: represents the regulator output voltage.
yww: represents the date code.
Please contact AME for details.
MSOP-8
Top View
AME 8844BEQAADJ
1. EN
2. VIN
3. ADJ
4. VOUT
5. GND
6. GND
7. GND
8. GND
n Ordering Information
AME8844 AEQA xxx
Voltage
150: V=1.5V
180: V=1.8V
250: V=2.5V
330: V=3.3V
Operating
Temperature
E:-40oC to 85oC
Pin Out T ypes
[Package T ype]
Q:MSOP-8
[Pin Count]
A:8
AME8844 BEQA ADJ
Voltage
ADJ: Adjustable
Operating
Temperature
E:-40oC to 85oC
Pin Out T ypes
[Package T ype]
Q:MSOP-8
[Pin Count]
A:8
1324
567
8
8844
Xyww
1324
567
8
8844
Byww
AME, Inc.
3
AME8844 750mA CMOS LDO
n Ordering Information (contd.)
Note: ww represents the date code
Please consult AME sales office or authorized Rep./Distributor for other output voltage and package type availability.
Part Number M ar ki ng O ut put Vol t age Package O per ating Temp. Range
AME8844AEQA150 8844
Lyww 1.50 MSOP-8 - 40oC to + 85oC
AME8844AEQA180 8844
Myww 1.80 MSOP-8 - 40oC to + 85oC
AME8844AEQA250 8844
Dyww 2.50 MSOP-8 - 40oC to + 85oC
AME8844AEQA330 8844
Ayww 3.30 MSOP-8 - 40oC to + 85oC
AME8844BEQAADJ 8844
Byww ADJ MSOP-8 - 40 oC to + 85oC
AME, Inc.
4
750mA CMOS LDO
AME8844
Maximum Unit
Thermal Resistance (θjc) MSOP-8 80 oC / W
Int ern al P o wer Di ssipati o n (P D)
(∆T = 100oC)* MSOP-8 W
150 oC
300 oC
M ax i m um Lead Tem perat ure (10 S ec)
Parameter
M ax i m um Junct i on Tem perat ure
Parameter Rating Unit
A m bient Tem perat ure Range - 40 to + 85 oC
Junct i on Tem perat ure - 40 to + 125 oC
n Absolute Maximum Ratings
n Recommended Operating Conditions
n Thermal Information
* Assuming a heat sink capable of twice times (θjc)
** Estimated
Caution: Stress above the listed absolute maximum rating may cause permanent damage to the device
Parameter Maximum Unit
Input V oltage 8 V
Out put Current PD / (VIN - VO)mA
Out put V ol tage GND - 0. 3 t o V IN + 0.3 V
ESD Classification B
AME, Inc.
5
AME8844 750mA CMOS LDO
Parameter Symbol Min Typ Max Units
Input V ol t age V IN Note 1 7 V
Out put V ol t age A ccurac y VO-1.5 1.5 %
VO(NOM)=1.5V 1000
VO(NOM)=1.8V 650
VO(NOM)>=2.0V 500
Out put Current IO750 mA
Current Lim i t ILIM 750 mA
S hort Circuit Current ISC 750 mA
Qui es cent Current IQ45 70 µA
Ground P i n Current IGND 45 µA
VO < 2.0V -0.15 0.15 %
4. 0 > V O > = 2. 0V -0. 1 0.02 0. 1 %
4. 0V <= VO-0.4 0.4 %
Load Regul at i on RE GLOAD -1 0.2 1 %
Over Tem erat ure Shutdown OTS 150 oC
Over Temerat ure Hyst eri s is OTH 30 oC
VO Tem perat ure Coeffi ci ent TC 30 ppm/oC
AD J In pu t Bia s Cu r re n t IADJ 1µA
M i nim um Load Current Iload 70 µA
A DJ Referenc e V ol t age V REF 1.221 1.240 1.26 V
f=1kHz 75
f=10kHz 55
f=100kHz 30
VEH 2.0 Vin V
VEL 00.4V
IEH 1µA
IEL 1µA
S hut down S uppl y Current ISD 0.5 2 µA
Out put Under V oltage VUV 84 %VO(NOM)
Out put Over V ol t age VOV 105 %VO(NOM)
P G Leakage Current ILC 1µA
P G V ol tage Low V OL 0.4 V
VPG=7V
ISINK=0.25mA
PSRR
eN
VIN=2.7V to 7V
VEN=VIN, VIN=2.7V to 7V
VEN=0V, VIN=2.7V to 7V
VIN=5V, VO=0V, VEN<VEL
P G goes Low when V OUT t oo Low
P G goes Low when V OUT t oo High
30 µVrms
E N Input Threshold VIN=2.7V to 7V
P ower Suppl y Rej ec t i on IO=100mA
CO=4.7µF ceramic
f= 10Hz to 100k Hz
IO=10mA Co=4.7µF
E N Input B i as Current
Out put V ol t age Nois e
Te st Condi tion
Dropout V ol t age V DROPOUT
Li ne Regul at i on
IO=1mA to 750mA
IO=0mA
See
chart
IO=750mA
VO=VON OM -2.0%
VIN=VO(NOM) +1V, VO < 0.4V
V i n = 2.5V
dB
IO=1mA
IO=1mA to 750mA
IO=1mA
VIN=VO+1 to VO+2
mV
VO>1.2V
VO>1.2V
REGLINE
n Electrical Specifications
VIN = VO(NOM) +2V, VEN = VIN, TA = 25OC unless otherwise noted
Note1:VIN(min)=VOUT+VDROPOUT
AME, Inc.
6
750mA CMOS LDO
AME8844
The AME8844 family of CMOS regulators contain a
PMOS pass transistor, voltage reference, error amplifier ,
over-current protection, and thermal shutdown.
The P-channel pass transistor receives data from the
error amplifier , over-current shutdown, and thermal pro-
tection circuits. During normal operation, the error am-
plifier compares the output voltage to a precision refer-
ence. Over-current and Thermal shutdown circuits be-
come active when the junction temperature exceeds
140oC, or the current exceeds 2.2A. During thermal shut-
down, the output voltage remains low. Normal operation
is restored when the junction temperature drops below
120oC.
The AME8844 behaves like a current source when the
load reaches 2.2A. However , if the load impedance drops
below 0.3 ohms, the current drops back to 600mA to
prevent excessive power dissipation. Normal operation
is restored when the load resistance exceeds 0.75 ohms.
n Detailed Description
n External Capacitors
The AME8844 is stable with an output capacitor to
ground of 4.7µF or greater . Ceramic capacitors have the
lowest ESR, and will offer the best AC performance. Con-
versely , Aluminum Electrolytic capacitors exhibit the high-
est ESR, resulting in the poorest AC response. Unfortu-
nately , large value ceramic capacitors are comparatively
expensive. One option is to parallel a 0.1µF ceramic
capacitor with a 10µF Aluminum Electrolytic. The benefit
is low ESR, high capacitance, and low overall cost.
A second capacitor is recommended between the in-
put and ground to stabilize Vin. The input capacitor should
be at least 0.1µF to have a beneficial effect.
All capacitors should be placed in close proximity to
the pins. A "Quiet" ground termination is desirable. This
can be achieved with a "Star" connection.
n Enable
When EN pin is pulled low , the PMOS pass transistor
shuts off, and all internal circuits are powered down. In
this state, the quiescent current is less than 2µA. This
pin behaves much like an electronic switch.
100K Ohm resistor is necessary between VEN source
and EN pin when VEN is higher than VIN.
n Adjustable V ersion
The adjustable version uses external feedback resis-
tors to generate an output voltage anywhere from 1.5V to
5.0V . V adj is trimmed to 1.24V and VOUT is given by the
equation:
VOUT = V adj ( 1 + R1 / R2 )
Feedback resistors R1 and R2 should be high enough
to keep quiescent current low, but increasing R1 + R2
will reduce stability . In general, R1 and R2 in the 10’ s of
kΩ will produce adequate stability , given reasonable lay-
out precautions. T o improve stability characteristics, keep
parasitics on the ADJ pin to a minimum, and lower R1
and R2 values.
n Power Good
The AME8844 includes the Power Good feature. When
the output is not within ±15% of the specified voltage, it
pulls low . This can occur under the following conditions:
1) Input V oltage too low .
2) During Over-Temperature.
3) During Over-Current.
4) If output is pulled up.
(Note: PG pin is an open-drain output.)
(Note: There is no internal pull-up for EN pin.
It can not be floating)
AME, Inc.
7
AME8844 750mA CMOS LDO
Dropout Voltage VS ILOAD
Quiescent Current vs. T emperature Ground Current vs. VIN
VOUT vs. Temperature(2.5V)Ground Current vs. Load Current
Dropout Voltage VS VOUT
Dropout Voltage (V)
I
LOAD
(A)
0
0.2
0.4
0.6
0.8
1
1.2
0 0.3 0.6 0.9 1.2 1.5 1.8
1.8
2.0
2.1
2.8
3.3
V
OUT
=1.5
Dropout Voltage (V)
V
OUT
(V )
0
0.2
0.4
0.6
0.8
1
02468
I
LOAD
=1.5A
I
LOAD
=1.0A
I
LOAD
=0.5A
Temp erature (
o
C)
Quiescent Current @ 5V (uA)
25
27
29
31
33
35
37
39
41
-45 -5 25 55 85 115
2.475
2.480
2.485
2.490
2.495
2.500
-45-5255585115
Output Voltage (V)
Temperature (
o
C)
Ground C urrent (µ
µµ
µA)
Load Current (mA)
34.5
35
35.5
36
36.5
37
37.5
38
38.5
0 0.25 0.5 0.75 1 1.25 1.5
VIN = 2.5V
VOUT = 1.5V
Ground Current (µ
µµ
µA)
VIN (V)
10
15
20
25
30
35
40
45
50
2345678
IOUT = 140mA
VOUT = 1.5V
AME, Inc.
8
750mA CMOS LDO
AME8844
Load Step 40mA to 1.5A
Dropout V oltage vs. Load Current(2.5V)
Line Transient Response
Load Regulation vs. Temperature
Current Limit Response
AME8844BEQA V ADJ vs. T emperature
Load Regulation (%)
Temperature (
o
C)
0.00
0.05
0.10
0.15
0.20
0.25
0.30
-45 -5 25 55 85 115
VIN (2V/DIV) VOUT (50mV/DIV)
Tim e (20m S /DIV)
C
IN
= 4.7
µ
F
C
OUT
= 4.7
µ
F
T
R
= T
F
= 1
µ
S
V OU T = 1.5V
0
VOUT 10mV/DIV ILoad 1A/DIV
Tim e 500
µ
µµ
µ
S/DIV
0
C
IN
= 4.7
µ
F
C
OUT
= 4.7
µ
F
V
IN
= 4.0V
V
OUT
= 1.8V
ILOAD 1A/DIV VOUT 1V/DIV
Tim e 1m S /D IV
I
LIM
I
SC
0A
0V
V
IN
= 5V
C
IN
= 4.7
µ
F
C
OUT
= 4.7
µ
F
VADJ (V)
Tem peratu re (
o
C)
1.235
1.236
1.237
1.238
1.239
1.240
1.241
1.242
1.243
1.244
-45 -5 25 55 85 115
0
50
100
150
200
250
300
350
400
0.3 0.6 0.9 1.2 1.5
115 oC
85 oC
55 oC
25 oC
-5 oC
-45 oC
Load Current (A)
Dropout Voltage @1.5A (mV)
AME, Inc.
9
AME8844 750mA CMOS LDO
Short Circuit Current vs. VIN
Overtemperature Shutdown Stability vs. ESR vs. ILoad
Stability vs. ESR vs. ILoad Stability vs. ESR vs. ILoad
Current Limit vs. VIN
1
1.2
1.4
1.6
1.8
2
2.2
2.4
2.6
2.8
3
2345678
Current Limit (A)
V
IN
(V )
C
IN
= 4.7
µ
F
C
OUT
= 4.7
µ
F
V
OUT
= 1.8V
Short Circuit Current (A)
V
IN
(V )
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
2345678
C
IN
= 4.7
µ
F
C
OUT
= 4.7
µ
F
VOUT 1V/DIV IOUT 1A/DIV
Tim e 100mS/DIV
0V
0A
V
IN
= 4V
C
IN
= 4.7
µ
F
C
OUT
= 4.
7µ
F
CLESR (Ω
Ω Ω
Ω )
IL O AD (mA)
0.01
0.1
1
10
100
1000
10000
0 250 500 750 1000 1250 1500
S table R egion
Untested R egion
Unstable Region
C
L
=5
µ
F
0.01
0.1
1
10
100
1000
10000
0250 500 750 1000 1250 1500
S table R egion
Untested R egion
Unstable R egion
C
L
=2
µ
F
CLESR (Ω
Ω Ω
Ω )
IL O AD (mA)
0.001
0.01
0.1
1
10
100
1000
10000
0 250 500 750 1000 1250 1500
S table R egion
Untested R egion
Unstable R egion
C
L
=10
µ
F
CLESR ( Ω
Ω Ω
Ω )
IL O AD (mA)
AME, Inc.
10
750mA CMOS LDO
AME8844
n External Resistor Divider Table
R1
(K Ohm) 1 2 5 10 20
Vout
1.30 20.67 41.33 103.33 206.67 413.33
1.35 11.27 22.55 56.36 112.73 225.45
1.40 7.75 15.50 38.75 77.50 155.00
1.45 5.90 11.81 29.52 59.05 118.10
1.50 4.77 9.54 23.85 47.69 95.38
1.55 4.00 8.00 20.00 40.00 80.00
1.60 3.44 6.89 17.22 34.44 68.89
1.65 3.02 6.05 15.12 30.24 60.49
1.70 2.70 5.39 13.48 26.96 53.91
1.75 2.43 4.86 12.16 24.31 48.63
1.80 2.21 4.43 11.07 22.14 44.29
1.85 2.03 4.07 10.16 20.33 40.66
1.90 1.88 3.76 9.39 18.79 37.58
1.95 1.75 3.49 8.73 17.46 34.93
2.00 1.63 3.26 8.16 16.32 32.63
2.05 1.53 3.06 7.65 15.31 30.62
2.10 1.44 2.88 7.21 14.42 28.84
2.15 1.36 2.73 6.81 13.63 27.25
2.20 1.29 2.58 6.46 12.92 25.83
2.25 1.23 2.46 6.14 12.28 24.55
2.30 1.17 2.34 5.85 11.70 23.40
2.35 1.12 2.23 5.59 11.17 22.34
2.40 1.07 2.14 5.34 10.69 21.38
2.45 1.02 2.05 5.12 10.25 20.50
2.50 0.98 1.97 4.92 9.84 19.68
2.55 0.95 1.89 4.73 9.47 18.93
2.60 0.91 1.82 4.56 9.12 18.24
2.65 0.88 1.76 4.40 8.79 17.59
2.70 0.85 1.70 4.25 8.49 16.99
2.75 0.82 1.64 4.11 8.21 16.42
2.80 0.79 1.59 3.97 7.95 15.90
2.85 0.77 1.54 3.85 7.70 15.40
2.90 0.75 1.49 3.73 7.47 14.94
2.95 0.73 1.45 3.63 7.25 14.50
3.00 0.70 1.41 3.52 7.05 14.09
3.05 0.69 1.37 3.43 6.85 13.70
3.10 0.67 1.33 3.33 6.67 13.33
R2(kohm)=(1.24*R1(kohm))/(Vout-1.24)
AME, Inc.
11
AME8844 750mA CMOS LDO
n External Resistor Divider Table (contd.)
Note: Small load(greater than 2 mA) is necessary as R1 or R2 is larger than 50 K Ohm. Otherwise, outputvoltage
probably cannot be pulled down to 0 V on disable mode.
R1
(K Ohm) 1 2 5 10 20
Vout
3.15 0.65 1.30 3.25 6.49 12.98
3.20 0.63 1.27 3.16 6.33 12.65
3.25 0.62 1.23 3.08 6.17 12.34
3.30 0.60 1.20 3.01 6.02 12.04
3.35 0.59 1.18 2.94 5.88 11.75
3.40 0.57 1.15 2.87 5.74 11.48
3.45 0.56 1.12 2.81 5.61 11.22
3.50 0.55 1.10 2.74 5.49 10.97
3.55 0.54 1.07 2.68 5.37 10.74
3.60 0.53 1.05 2.63 5.25 10.51
3.65 0.51 1.03 2.57 5.15 10.29
3.70 0.50 1.01 2.52 5.04 10.08
3.75 0.49 0.99 2.47 4.94 9.88
3.80 0.48 0.97 2.42 4.84 9.69
3.85 0.48 0.95 2.38 4.75 9.50
3.90 0.47 0.93 2.33 4.66 9.32
3.95 0.46 0.92 2.29 4.58 9.15
4.00 0.45 0.90 2.25 4.49 8.99
4.05 0.44 0.88 2.21 4.41 8.83
4.10 0.43 0.87 2.17 4.34 8.67
4.15 0.43 0.85 2.13 4.26 8.52
4.20 0.42 0.84 2.09 4.19 8.38
4.25 0.41 0.82 2.06 4.12 8.24
4.30 0.41 0.81 2.03 4.05 8.10
4.35 0.40 0.80 1.99 3.99 7.97
4.40 0.39 0.78 1.96 3.92 7.85
4.45 0.39 0.77 1.93 3.86 7.73
4.50 0.38 0.76 1.90 3.80 7.61
4.55 0.37 0.75 1.87 3.75 7.49
4.60 0.37 0.74 1.85 3.69 7.38
4.65 0.36 0.73 1.82 3.64 7.27
4.70 0.36 0.72 1.79 3.58 7.17
4.75 0.35 0.71 1.77 3.53 7.07
4.80 0.35 0.70 1.74 3.48 6.97
4.85 0.34 0.69 1.72 3.43 6.87
4.90 0.34 0.68 1.69 3.39 6.78
4.95 0.33 0.67 1.67 3.34 6.68
5.00 0.33 0.66 1.65 3.30 6.60
R2(kohm)=(1.242*R1(kohm))/(Vout-1.242)
AME, Inc.
12
750mA CMOS LDO
AME8844
WITH PLATING
BASE METAL
e
R0.127(0.005) TYP
ALL CORNER
& EDGES
TOP PKG.
Top View
Fron t View
End View
E
E1
PIN 1 I.D
(SHINNY SURFAC E)
D
e1
BTM PKG.
L
L1
L2
DETAIL A
b
A1
A2
A
b
b1
c1c
B
SECTI ON B- B
E1
B
See Detail A
£c
MIN MAX MIN MAX
A- 1.07 - 0.04197
A10.05 0.20 0.002 0.008
A2 0.81 0.92 0.032 0.036
b0.28 0.38 0.011 0.015
b1 0.28 0.33 0.011 0.013
c0.13 0.23 0.005 0.009
c1 0.13 0.17 0.005 0.006
D2.90 3.10 0.114 0.122
E4.77 4.98 0.188 0.196
E1 2.90 3.10 0.114 0.122
e
e1
L0.406 0.686 0.01598 0.02701
L1
L2
è0o8o0o8o
SYMBOLS MILLIMETERS INCHES
0.65 T YP 0.0255 T YP
1.95 T YP 0.0767 T YP
0.94 REF 0.037 RE F
0.010 T YP0.254 T YP
n Package Dimension
MSOP-8
NOTE:
1. Controlling dimension : Millimeter, converted inchdimension
are not necessarily exact.
2. Dimensiioning and tolerancing per ansi Y14.5m-1994.
3. Dimension "d" does not include mold flash,protrusion or gate
burr, mold flash,protrusion and gate burr shall not exceed
0.15mm(0.006") per side. Dimension e1 do not include inter-lead
flash or protrusion, inter-lead flash and protrusion shall not
exceed 0.15mm(0.006") per side.
4. The package top be smaller than the package bottom. Dimen-
sion d and e1 are determined at outermost extremes of the
plastic body exclusive of mold flash, tie bar burrs, gate burrs
and interlead flash, but including any mismatch between the top
and bottom of the plastic body.
5. Dimension 'b' does not include dambar protrusion. Allowable
dambar protrusion shall be 0.08mm(0.0031) total in excess of
the "b" dimension at maximum material condition.
AME, Inc.
13
AME8844 750mA CMOS LDO
n Tape and Reel Diagram
P
PIN 1
W
Carrier Tape, Number of Components Per Reel and Reel Size
P ac kage Carrier Wi dt h (W ) P itc h (P ) P art P er Ful l Reel Reel S ize
MSOP-8L 12mm 9.1mm 4000 13in
Life Support Policy:
These products of AME, Inc. are not authorized for use as critical components in life-support
devices or systems, without the express written approval of the president
of AME, Inc.
AME, Inc. reserves the right to make changes in the circuitry and specifications of its devices and
advises its customers to obtain the latest version of relevant information.
AME, Inc. , July 2003
Document: 2013-DS8844-E
Corporate Headquarter U.S.A. (Subsidiary)
AME, Inc. Analog Microelectronics, Inc.
2F, 189 Kang-Chien Road, Nei-Hu Dist. 3100 De La Cruz Blvd. Suite 201
Taipei 1 14 Taiwan, R.O.C. Santa Clara, CA. 95054-2046
Tel: 886 2 2627-8687 Tel : (408) 988-2388
Fax: 886 2 2659-2989 Fax: (408) 988-2489
www.ame.com.tw
E-Mail: sales@ame.com.tw
