08/2001
1
S2
12 Pin 4 Sided SQFP
Package
FEATURES
Single +5 Volt Supply
Automatic Gain Control
-43 dBm Sensitivity
0 dBm Optical Overload
70 MHz Bandwidth
APPLICATIONS
OC-1 Receiver
FITL
Low Noise RF Amplifier
Figure 1: ATA00501 Equivalent Circuit
ATA00501
AGC Transimpedance Amplifier
SONET OC-1
PRELIMINARY DATA SHEET-Rev 1.5
VDD1
I
IN
GND
GND
GND GND
GND
GND
GND
GND
C
BY
C
BY
C
AGC
V
OUT
1992
19F
V
DD2
D1C
The ANADIGICS ATA00501 is a 5V low noise
transimpedance amplifier with AGC designed to be
used in OC-1 fiber optic links. The device is used in
conjunction with a photodetector (PIN diode or
avalanche photodiode) to convert an optical signal
into an output voltage. The ATA00501 has a bandwidth
of 70MHz and a dynamic range in excess of 40dB. It
is manufactured in a GaAs MESFET process and
available in bare die form or a 12 pin SQFP package.
PRODUCT DESCRIPTION
V
DD
V
OUT
C
AGC
GND
I
IN
C
BY
Photodetector cathode must be connected
To I
IN
for proper AGC operation
PATENT PENDING
GND
or
neg.supply
VGA
- 35
70K
+
4pF
+ 0.8
AGC
60K
20pF
PRELIMINARY DATA SHEET - Rev 1.5
08/2001
21.
ATA00501
Table 1: ATA00501D1C Pad Description (Die Only)
Figure 2: Bonding Pad Layout (Die Only)
ELECTRICAL CHARACTERISTICS
Table 3: Absolute Maximum Ratings
D
A
P
N
O
I
T
P
I
R
C
S
E
D
T
N
E
M
M
O
C
1
D
D
V
1
D
D
V
e
g
a
t
s
n
i
a
g
t
u
p
n
i
r
o
f
y
l
p
p
u
s
e
v
it
i
s
o
P
2
D
D
V
2
D
D
V
e
g
a
t
s
n
i
a
g
d
n
o
c
e
s
r
o
f
y
l
p
p
u
s
e
v
it
i
s
o
P
N
II
t
n
e
r
r
u
C
t
u
p
n
I
A
I
T
n
o
it
a
r
e
p
o
r
e
p
o
r
p
r
o
f
e
d
o
h
t
a
c
r
o
t
c
e
t
e
d
t
c
e
n
n
o
C
T
U
O
V
e
g
a
tl
o
V
t
u
p
t
u
O
A
I
T
k
c
o
l
b
C
D
l
a
n
r
e
t
x
e
s
e
ri
u
q
e
R
C
G
A
C
r
o
ti
c
a
p
a
C
C
G
A
l
a
n
r
e
t
x
E
t
n
a
t
s
n
o
c
e
m
it
C
G
A
=
C
G
A
C
*
K
0
7
Y
B
C
r
o
ti
c
a
p
a
c
s
s
a
p
y
b
e
g
a
t
s
n
i
a
g
t
u
p
n
I
F
p
6
5
>
925 um
VDD1
I
IN
GND
GND
GND GND
GND
GND
GND
GND
C
BY
C
BY
C
AGC
V
OUT
1992
19F
1250 um
V
DD2
V
1
D
D
V
0
.
7
V
2
D
D
V
0
.
7
I
N
I
A
m
5
T
A
0
4
-
.
p
m
e
T
g
n
it
a
r
e
p
O
o
5
2
1
o
t
C
o
C
T
S
5
6
-
.
p
m
e
T
e
g
a
r
o
t
S
o
0
5
1
o
t
C
o
C
Figure 3: Pin Layout
1
2
3
4
5
6
7
8
9
10
11
12
Table 2:ATA00501S2C Pin Description
Stresses in excess of the absolute ratings
may cause permanent damage. Functional
operation is not implied under these
conditions. Exposure to absolute ratings for
extended periods of time may adversely
affect reliability.
N
I
P
N
O
I
T
P
I
R
C
S
E
D
N
I
P
N
O
I
T
P
I
R
C
S
E
D
1
C
N
7
V
T
U
O
2
D
N
G
8
D
N
G
3
I
N
I
9
C
N
4
C
Y
B
0
1
V
D
D
5
D
N
G
1
1
D
N
G
6
C
C
G
A
2
1
C
N
PRELIMINARY DATA SHEET - Rev 1.5
08/2001
3
ATA00501
Table 4: Electrical Specifications
Notes:
(1) f=50MHz
(2) Measured with IIN below AGC Threshold. During AGC, input impedance will decrease propor-
tionally to I
IN
(3) Defined as the IIN where Transresistance has decreased by 50%.
(4) See note on Indirect Measurement of Optical Overload.
(5) See note on Measurement of Input Referred Noise Current.
(6) C
AGC
= 56 pF
(7) Parameter is guaranteed (not tested) by design and characterization data @ 51Mb/s, assuming
detector responsivity of 0.9
R
E
T
E
M
A
R
A
P
N
I
M
P
Y
T
X
A
M
T
I
N
U
)
A
n
0
0
5
<
c
d
I,
=
L
R
(
e
c
n
a
t
s
i
s
e
r
s
n
a
r
T
5
5
K
R
(
e
c
n
a
t
s
i
s
e
r
s
n
a
r
T
L
)
0
5
=
)
1
(
5
1
8
2
K
B
d
3
-
h
ti
w
d
n
a
B
0
5
0
7
z
H
M
e
c
n
a
t
s
i
s
e
R
t
u
p
n
I
)
2
(
0
0
5
1
e
c
n
a
t
s
i
s
e
R
t
u
p
t
u
O
0
3
0
5
0
6
e
g
a
tl
o
V
t
e
s
ff
O
t
u
p
n
I
5
.
1
6
.
1
9
.
1
s
tl
o
V
e
g
a
tl
o
V
t
e
s
ff
O
t
u
p
t
u
O
8
.
1
s
tl
o
V
tf
ir
D
e
g
a
tl
o
V
t
e
s
ff
O
1
/
V
m
o
C
I
(
d
l
o
h
s
e
r
h
T
C
G
A
N
I
)
)
3
(
5
0
1
A
d
a
o
lr
e
v
O
l
a
c
it
p
O
)
4
(
3
-
0
m
B
d
t
n
a
t
s
n
o
C
e
m
i
T
C
G
A
)
6
(
6
1
c
e
s
E
I
D
-
y
ti
v
it
i
s
n
e
S
l
a
c
it
p
O
)
7
(
3
4
-
m
B
d
P
F
Q
S
-
y
ti
v
it
i
s
n
e
S
l
a
c
it
p
O
)
7
(
1
4
-
m
B
d
t
n
e
r
r
u
C
y
l
p
p
u
S
0
3
5
4
A
m
e
g
n
a
R
e
g
a
tl
o
V
g
n
it
a
r
e
p
O
5
.
4
+
0
.
5
+
0
.
6
+
s
tl
o
V
e
g
n
a
R
e
r
u
t
a
r
e
p
m
e
T
g
n
it
a
r
e
p
O
0
4
-
5
8
o
C
m
m
W
W
W
W
PRELIMINARY DATA SHEET - Rev 1.5
08/2001
41.
ATA00501
Figure 4: ATA 00501D1C Typical Bonding
APPLICATION INFORMATION
Power Supplies and General Layout
Considerations
The ATA00501S2C may be operated from a positive
supply as low as + 4.5 V and as high as + 6.0 V.
Below + 4.5 V, bandwidth, overload and sensitivity
will degrade, while at + 6.0 V, bandwidth, overload
and sensitivity improve (see Bandwidth vs.
Temperature curves). Use of surface mount, low
inductance power supply bypass capacitors
(>=56pF) are essential for good high frequency and
low noise performance. The power supply bypass
capacitors should be mounted on or connected to a
good low inductance ground plane.
General Layout Considerations
Since the gain stages of the transimpedance
amplifier have an open loop bandwidth in excess
of 1.0 GHz, it is essential to maintain good high
frequency layout practices. To prevent oscillations,
a low inductance RF ground plane should be made
available for power supply bypassing. Traces that
can be made short should be made short, and the
utmost care should be taken to maintain very low
capacitance at the photodiode-TIA interface (I
IN
),
excess capacitance at this node will cause a
degradation in bandwidth and sensitivity (see
Bandwidth vs. CT curves).
PIN
56pF
56pF
V
DD
OUT
56pF
56pF
GND
VDD2
GND
GND
1992
V
OUT
GND
GND
C
BY
C
AGC
C
BY
GND
GND
GND
GND
I
IN
60C
V
DD
Figure 6: Bandwidth vs. Temperature
0.04
0.05
0.06
0.07
0.08
0.09
-40
10
60
85
V
DD
=
4.5 V
V
DD
=
5.0 V
V
DD
=
5.5 V
C
T
= 0.5 pF
Temperature (C)
Bandwidth
(GHz)
Figure 5: ATA 00501S2C External Circuit
1
2
3
4
5
6
7
8
9
10
11
12
I
IN
NC
GND
or
Neg.Supply
0.1F
Vout
NC
0.1F
V
DD
NC
56 pF
56 pF
PRELIMINARY DATA SHEET - Rev 1.5
08/2001
5
ATA00501
Note: All performance curves are typical @ TA =25 oC
unless otherwise noted.
IIN Connection
(Refer to the equivalent circuit diagram.) Bonding
the detector cathode to IIN (and thus drawing current
from the ATA00501) improves the dynamic range.
Although the detector may be used in the reverse
direction for input currents not exceeding 25
m
A, the
specifications for optical overload will not be met.
VOUT Connection
The output pad should be connected via a coupling
capacitor to the next stage of the receiver channel
(filter or decision circuits), as the output buffers are
not designed to drive a DC coupled 50 ohm load
(this would require an output bias current of
approximately 36 mA to maintain a quiescent 1.8
Volts across the output load). If VOUT is connected
to a high input impedance decision circuit (>500
ohms), then a coupling capacitor may not be
required, although caution should be exercised
since DC offsets of the photo detector/TIA
combination may cause clipping of subsequent gain
or decision circuits.
Figure 7: Bandwidth vs. CT
V
DD
= 4.5 V
V
DD
= 5.0 V
V
DD
= 5.5 V
90
80
70
60
50
40
30
0 0.2 0.4 0.6 0.8 1 1.2
B(3dB) A/ 2
Rf (C
in
+C
t
)
C
T
(pF)
Bandwidth
(MHz)
Figure 8: Transimpedance vs. I
IN
V
DD
= 5.5 V
V
DD
= 4.5 V
I
IN
(mA DC)
-2.1 -1.6 -1.1 -0.6 -0.1
25
22
19
16
13
10
7
4
1
I
IN
50
Transimpedance
(K
Ohm)
Figure 9: Bandwidth vs. I
IN
Figure 10: V
OUT
vs. I
IN
V
DD
= 4.5 V
V
DD
= 5.5 V
50
I
IN
- 2.1 - 1.6 - 1.1 - 0.6 - 0.1
1.44
1.24
1.04
.84
.64
.44
.24
.04
R
f
Bandwidth
(GHz)
I
IN
(mA DC)
V
DD
= 4.5 V
V
DD
= 5.5 V
Output Collapse
I
IN
v
OUT
Heavy AGC
Linear Region
(
o
3.4
3.2
3.0
2.9
2.7
2.5
2.4
2.2
2.0
1.9
1.7
1.5
1.4
1.2
1.0
0.8
0.7
0.5
0.3
0.2
0.0
R
f
-4 - 3 - 2 - 1
I
IN
(mA DC)
V
O
U
T
(
V
olt
s
)
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