33
www.ptcc.com.tw
AS1004
Micropower Voltage Reference
SEMICONDUCTOR
Features
Low voltage reference
10 A turn-on current for AS1004-1.2
20 A turn-on current for AS1004-2.5
4 mV (0.3%) initial accuracy for
AS1004-1.2
20 mV (0.8%) initial accuracy for
AS1004-2.5
Guaranteed operation to 20 mA. Over
three orders of magnitude of operating
current!
Temperature performance guaranteed
Very low dynamic impedance
Description
The AS1004 is a two-terminal precision bandgap voltage reference
with a low turn-on current of 10 A.
Emulating a 1.235 V zener diode, the AS1004 operates more than
three orders of magnitude of output current with minute output imped-
ance and guaranteed stability. With an initial tolerance of 4 mV and
guaranteed temperature performance, it is ideal for precision instru-
mentation, especially in low power applications. Being a low-voltage
reference, the AS1004 is also well-suited as a reference for low-volt-
age power supply applications, especially in power supplies intended
for low-voltage logic systems, laptop computers and other portable or
battery operated equipment.
The AS1004 is pin-for-pin compatible with the LT1004 and the LM385
and offers improved specifications over both the LM385 and the
MP5010. It is also available as a 2.5 V reference with a guaranteed
start-up current of 20 A.
Pin Configuration --
Top view
Ordering Information
ANODE
TO-92 (LP)
8L SOIC (8D)
CATHODE
N/C
N/C
CATHODE
N/C
CATHODE
ANODE
N/C
N/C
N/C
ANODE
SOT-89 (S)
ANODE
CATHODE
1
2
3
4
8
7
6
5
Circuit Type:
Micropower Voltage Reference
Reference Voltage:
A = 1.235V
B = 2.50V
Temperature Range:
A = 0
C to 70
C
Packaging Option:
A
B
T
N
Package Style:
8D
LP
S
= Ammo Pack
= Bulk
= Tube
= Tape and Reel (13" Reel Dia)
= 8 Pin, Plastic SOIC
= TO-92
= SOT-89
AS1004 A A 8D N
34
www.ptcc.com.tw
AS1004
Micropower Voltage Reference
Simplified Schematic
Q13
Q12
R10
R11
R12
Q14
Q9
Q10
Q11
C3
Q7
R4
C2
Q4
R2
Q3
C1
Q1
Q5
R6
R7
Q8
Q6
K
A
Absolute Maximum Ratings
Parameter
Symbol
Rating
Units
Reverse Breakdown Current
I
Z
30
mA
Forward Current
I
F
30
mA
Continuous Power Dissipation at 25C
P
D
TO-92
775
mW
8L SOIC
750
mW
SOT-89
1000
mW
Maximum Junction Temperature
T
J
150
C
Storage Temperature
T
STG
65 to 150
C
Lead Temperature, Soldering 10 Seconds
T
L
300
C
Recommended Conditions
Parameter
Symbol
Rating
Unit
Cathode Current
I
Z
100
A
Typical Thermal Resistances
Package
JA
JC
Typical Derating
TO-92
160C/W
80C/W
6.3 mW/C
8L SOIC
175C/W
45C/W
5.7 mW/C
SOT-89
110C/W
8C/W
9.1 mW/C
35
www.ptcc.com.tw
AS1004
Micropower Voltage Reference
Electrical Characteristics
Electrical Characteristics are guaranteed over full junction temperature range (0 to 70C). Ambient temperature must be derated
based on power dissipation and package thermal characteristics.
AS1004-1.2
AS1004-2.5
Parameter
Symbol
Test Condition
Min.
Typ.
Max.
Min.
Typ.
Max.
Unit
Reverse Breakdown Voltage
V
Z
I
Z
= 100 A, T
J
= 25C
1.231
1.235
1.239
2.480
2.500
2.520
V
0C
T
A
70C
1.225
1.235
1.245
2.470
2.500
2.530
V
Average Temperature
V
Z
/
T
I
min
I
Z
20 mA
20
60
ppm/C
Coefficient
Minimum Operating Current
I
Z (min)
4
10
12
20
A
Reverse Breakdown Voltage
V
Z
/
I
Z
I
min
I
Z
1 mA
0.5
1
0.5
1
mV
Change With Current
Over Temperature
0.5
1.5
0.5
1.5
mV
1 mA
I
Z
20 mA
6.5
10
6.5
10
mV
Over Temperature
6.5
20
6.5
20
mV
Reverse Dynamic Impedance
Z
Z
I
Z
= 100 mA, f = 25 Hz
0.2
0.6
0.8
0.9
Over Temperature
1
1.5
1.5
Wide Band Noise
e
n
I
Z
= 100 A
10 Hz
f
10 KHz
60
60
V
Long Term Stability
V
Z
/
T
I
Z
= 100 A
T
A
= 25C 0.1C
20
60
ppm/kH
0
0
5
10
5000
0.5
0
10
0.025 mV/
C
0.002%/
C
20 ppm/
C
30
20
60
50
40
70
ppm
mV
%
V
REF
T
T
V
REF
Temperature (
C)
0
Average Temperature Coefficient =
Calculating Average Temperature
Coefficient for the AS1004-1.2 Reference
55
35
15
5
25
T
A
Ambient Temperature (
C)
45
65
85
105
125
1.245
1.240
1.235
V
Z
Reference V
oltage (V)
1.230
1.225
AS1004-1.2 Reference Voltage vs. Ambient Temperature
I
Z
= 100
A
Typical Performance Curves
Figure 1
Figure 2
36
www.ptcc.com.tw
AS1004
Micropower Voltage Reference
0
0
5
10
5000
0.5
0
10
0.046 mV/
C
0.004%/
C
37 ppm/
C
30
20
60
50
40
70
ppm
mV
%
V
REF
T
T
V
REF
Temperature (
C)
0
Average Temperature Coefficient =
Calculating Average Temperature
Coefficient for the AS1004-2.5 Reference
55
35
15
5
25
T
A
Ambient Temperature (
C)
45
65
85
105
125
2.52
2.51
2.50
V
Z
Reference V
oltage (V)
2.49
2.48
AS1004-2.5 Reference Voltage
versus Ambient Temperature
I
Z
= 100
A
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
V
R
Reverse Voltage (V)
I
R
Reverse Current (
A)
0.1
1
10
100
AS1004-1.2 Reverse Operating Characteristics
T
A
= 55
C to 125
C
0
0.5
1.0
1.5
2.0
2.5
3.0
V
R
Reverse Voltage (V)
0.1
1
10
100
I
R
Reverse Current (
A)
AS1004-2.5 Reverse Operating Characteristics
T
A
= 55
C to 125
C
Typical Performance Curves
Figure 3
Figure 4
Figure 5
Figure 6
37
www.ptcc.com.tw
AS1004
Micropower Voltage Reference
0.01
0.1
1
10
100
4
0
4
8
12
16
I
R
Reverse Current (mA)
AS1004-1.2 Change in Reference
Voltage versus Reverse Current
V
z Change in Reference V
oltage (mA)
T
A
= 55
C to 125
C
I
R
Reverse Current (mA)
0.01
0.1
1
10
100
4
0
4
8
12
16
AS1004-2.5 Change in Reference
Voltage versus Reverse Current
V
z Change in Reference V
oltage (mA)
T
A
= 55
C to 125
C
0
50
t Time (
s)
100
500
600
0
5
0
0.5
1.0
1.5
36 k
V
O
V
I
OUTPUT
INPUT
AS1004-1.2 Transient Response
Input and Output V
oltage (V)
0
50
t Time (
s)
100
500
600
OUTPUT
INPUT
AS1004-2.5 Transient Response
0
5
0
1
2
3
Input and Output V
oltage (V)
V
O
V
I
36 k
Typical Performance Curves
Figure 7
Figure 8
Figure 9
Figure 10
38
www.ptcc.com.tw
AS1004
Micropower Voltage Reference
0.01
0.1
1
10
100
1 k
10 k
1 k
100
10
1
0.1
Z
Z
Reference Impedance (
)
f = Frequency (kHz)
t
Z
= 100
A
T
A
= 25
C
AS1004-1.2 Reverse Dynamic Impedance
Z
Z
Reference Impedance (
)
AS1004-2.5 Reverse Dynamic Impedance
0.01
0.1
1
10
100
1 k
10 k
1 k
100
10
1
0.1
f = Frequency (kHz)
t
Z
= 100
A
T
A
= 25
C
Forward Characteristics
0.01
0.1
1
10
100
I
F
= Forward Current (mA)
1.2
0.8
0.4
0
V
F
For
ward V
oltage (V)
T
A
= 25
C
Z
Z
Reference Impedance (
)
0.01
0.1
1
10
100
I
Z
Reverse Current (mA)
100
Low Frequency Reverse Dynamic Impedance
10
1
0.1
T
A
= 55
C to 125
C
f = 25 Hz
Typical Performance Curves
Figure 11
Figure 12
Figure 13
Figure 14
39
www.ptcc.com.tw
AS1004
Micropower Voltage Reference
Typical Applications
+
3 k
V
IN
OUT
AS1004-1.2
Figure 15
100 k
V
IN
OUT
AS1004-2.5
Figure 16
1.235V Reference
2.5V Reference
100 k
V
IN
AS1004-2.5
Figure 17
Low Noise Reference
12 V
86.7 k
500 k
500 k
AS1004-1.2
LO = Battery Low
150 pF
Lead Acid Low Battery Detector
Micropower 10V Reference
LM338
AS1004-2.5
ADJ
V
IN
V
IN
8 V
V
IN
= 12 V to 20 V
R
V
22
F
V
OUT
5 V OUT
976
, 1%
324
, 1%
Figure 19
+
High Stability 5V Regulator
LM317
AS1004-2.5
ADJ
V
IN
V
IN
10
F
0.1
F
50
F
V
OUT
OUT
200
Figure 18
Figure 21
Figure 20
+
Variable Output Regulator
5 k
V
1V
0.015 mA
LM4250
+
AS1004-1.2
1 M
7
3
2
4
8
6
22 M
150 pF
3.5 M
500 k
OUT
PDF 
ZIP