Micrel, Inc.
3.3V/5V 622Mbps PECL LOW-POWER
LIMITING POST AMPLIFIER W/PECL
SIGNAL DETECT
DESCRIPTION
SY88713V
SY88713V
FEATURES
s
s
s
s
s
Single 3.3V or 5V power supply
Up to 622Mbps operation
Low noise PECL data outputs
Chatter-free PECL Signal Detect (SD) output
TTL /EN input
s
Programmable SD level set (SD
LVL
)
s
Available in a tiny 10-pin MSOP (3mm) package
APPLICATIONS
s
622Mbps SONET/SDH
s
Small form factor transceivers
s
High-gain line driver and line receiver
The SY88713V low-power limiting post amplifier is
designed for use in fiber optic receivers. The device connects
to typical transimpedance amplifiers (TIAs). The linear signal
output from TIAs can contain significant amounts of noise
and may vary in amplitude over time. The SY88713V
quantizes these signals and outputs PECL level waveforms.
The SY88713V operates from a single +3.3V or +5V
power supply, over temperatures ranging from –40°C to
+85°C. With its wide bandwidth and high gain, signals with
data rates up to 622Mbps and as small as 5mVp-p can be
amplified to drive devices with PECL inputs.
The SY88713V generates a PECL SD output. A
programmable signal-detect level set pin (SD
LVL
) sets the
sensitivity of the input amplitude detection. SD asserts high
if the input amplitude rises above the threshold set by SD
LVL
and deasserts low otherwise. /EN deasserts the true output
signal without removing the input signal. Typically 4.6dB
SD hysteresis is provided to prevent chattering.
TYPICAL APPLICATIONS CIRCUIT
120Ω
V
CC
SD
From
Transimpedance
Amp.
0.1µF
0.1µF
50Ω
D
IN
/D
IN
50Ω
/EN
D
OUT
0.1µF
0.1µF
R
pd
SY88713V
SD
LVL
V
CC
V
REF
/D
OUT
R
pd
To
CDR
GND
100Ω
3kΩ
GND
For 3.3V, R
pd
= 120Ω
For 5V, R
pd
= 220Ω
M9999-072505
hbwhelp@micrel.com or (408) 955-1690
Rev.: B
Amendment: /0
1
Issue Date: July 2005
Micrel, Inc.
SY88713V
PACKAGE/ORDERING INFORMATION
/EN 1
DIN 2
/DIN 3
VREF 4
LOSLVL 5
10 VCC
9 DOUT
8 /DOUT
7 /LOS
6 GND
Ordering Information
Part Number
SY88713VKC
SY88713VKCTR
(1)
SY88713VKG
Package
Type
K10-1
K10-1
K10-1
K10-1
Operating
Range
Commercial
Commercial
Industrial
Industrial
Package
Marking
713V
713V
713V with
Pb-Free bar-line indicator
713V with
Pb-Free bar-line indicator
Lead
Finish
Sn-Pb
Sn-Pb
Pb-Free
NiPdAu
Pb-Free
NiPdAu
10-Pin MSOP
(K10-1)
SY88713VKGTR
(1)
Note:
1. Tape and Reel.
PIN DESCRIPTION
Pin Number
1
2
3
4
5
Pin Name
/EN
DIN
/DIN
VREF
SDLVL
Input
Type
TTL Input:
Default is high.
Data Input
Data Input
Pin Function
Enable: Deasserts true data output when high.
True data input.
Complementary data input.
Reference voltage.
Signal-Detect Level Set: A voltage between V
CC
and V
REF
on this pin
sets the threshold for the data input amplitude at which SD will be
asserted.
Device ground.
Signal-Detect: Asserts high when the data input amplitude rises above
the threshold set by SD
LVL
.
Complementary data output.
True data output.
Positive power supply.
6
7
8
9
10
GND
SD
/DOUT
DOUT
VCC
Ground
PECL Output
PECL Output
PECL Output
Power Supply
M9999-072505
hbwhelp@micrel.com or (408) 955-1690
2
Micrel
SY88713V
Absolute Maximum Ratings
(Note 1)
Supply Voltage (V
CC
) ....................................... 0V to +7.0V
Input Voltage (D
IN
, /D
IN
) .........................................0 to V
CC
Output Current (I
OUT
)
Continuous ............................................................. 50mA
Surge .................................................................... 100mA
/EN Voltage ............................................................ 0 to V
CC
V
REF
Current ......................................... –800µA to +500µA
SD
LVL
Voltage ........................................................0 to V
CC
Lead Temperature (soldering, 20 sec.) ................... +260°C
Storage Temperature (T
S
) ....................... –55°C to +125°C
Note 1.
Operating Ratings
(Note 2)
Supply Voltage (V
CC
) .............................. +3.0V to +3.6V or
............................................................ +4.5V to +5.5V
Ambient Temperature (T
A
),
Note 3 ............
–40°C to +85°C
Junction Temperature (T
J
),
Note 3 ..........
–40°C to +120°C
Package Thermal Resistance
MSOP
(θ
JA
) Still-Air .................................................. 113°C/W
(ψ
JB
) Still-Air .................................................... 74°C/W
Permanent device damage may occur if ABSOLUTE MAXIMUM RATINGS are exceeded. This is a stress rating only and functional operation is
not implied at conditions other than those detailed in the operational sections of this data sheet. Exposure to ABSOLUTE MAXIMUM RATlNG
conditions for extended periods may affect device reliability.
The data sheet limits are not guaranteed if the device is operated beyond the operating ratings.
Commercial devices are guaranteed from 0°C to +85°C ambient temperature.
Note 2.
Note 3.
DC ELECTRICAL CHARACTERISTICS
(Note 1)
V
CC
= 3.0V to 3.6V or 4.5V to 5.5V; R
LOAD
= 50Ω to V
CC
–2V; T
A
= –40°C to +85°C; typical values at V
CC
= 3.3V, T
A
= 25°C
Symbol
I
CC
SD
LVL
V
IH
V
IL
I
IH
I
IL
V
OH
V
OL
V
OFFSET
V
IHCMR
V
REF
Note 1.
Note 2.
Note 3.
Parameter
Power Supply Current
SD
LVL
Voltage
/EN Input HIGH Voltage
/EN Input LOW Voltage
/EN Input HIGH Current
/EN Input LOW Current
PECL Output HIGH Voltage
PECL Output LOW Voltage
Differential Output Offset
Common Mode Range
Reference Voltage
Specification for packaged product only.
Condition
no output load
Min
Typ
21
Max
40
V
CC
0.8
Units
mA
V
V
V
µA
µA
mA
V
V
mV
V
V
V
REF
2.0
V
IN
= 2.7V
V
IN
= V
CC
V
IN
= 0.5V
50Ω to V
CC
–2V output load
50Ω to V
CC
–2V output load
Note 2
Note 3
–0.3
20
100
V
CC
–1.085 V
CC
–0.955 V
CC
–0.880
V
CC
–1.830 V
CC
–1.705 V
CC
–1.555
±100
GND +1.7
V
CC
–1.38
V
CC
–1.32
V
CC
V
CC
–1.26
The V
IHCMR
range is referenced to the most positive side of the differential input signal.
The current provided into or from V
REF
must be limited to 800µA source and 500µA sink.
3
Micrel
SY88713V
AC ELECTRICAL CHARACTERISTICS
(Note 1)
V
CC
= 3.0V to 3.6V or 4.5V to 5.5V; R
LOAD
= 50Ω to V
CC
–2V; T
A
= –40°C to +85°C; typical values at V
CC
= 3.3V, T
A
= 25°C
Symbol
HYS
t
OFF
t
ON
t
r
,t
f
V
ID
V
OD
V
SR
A
V(Diff)
B
–3dB
S
21
Note 1.
Parameter
SD Hysteresis
SD Release Time
SD Assert Time
Differential Output Rise/Fall Time
(20% to 80%)
Differential Input Voltage Swing
Differential Output Voltage Swing
SD Sensitivity Range
Differential Voltage Gain
3dB Bandwidth
Single-Ended Small-Signal Gain
Specification for packaged product only.
Condition
electrical signal
Min
2
Typ
4.6
0.1
0.2
Max
8
0.5
0.5
400
Units
dB
µs
µs
ps
mVp-p
mVp-p
mVp-p
5
V
ID
≥
18mVp-p
V
ID
=
5mVp-p
5
38
700
26
32
1500
400
1800
50
mVp-p
dB
MHz
dB
TYPICAL OPERATING CHARACTERISTICS
100
90
80
70
60
50
40
30
20
10
0
3.3V SD Assert and Deassert
Levels vs. SD
LVL
3.3V
T
A
= 25°C
622Mbps
Pattern 2
23
-1
100
90
80
70
60
50
40
30
20
10
0
5V SD Assert and Deassert
Levels vs. SD
LVL
5.0V
T
A
= 25°C
622Mbps
Pattern 2
23
-1
V
ID
(mVp-p)
0
-0.2 -0.4 -0.6 -0.8 -1.0 -1.2
SD
LVL
(referenced to V
CC
) (V)
V
ID
(mVp-p)
0
-0.2 -0.4 -0.6 -0.8 -1.0 -1.2
SD
LVL
(referenced to V
CC
) (V)
4
Micrel, Inc.
SY88713V
DETAILED DESCRIPTION
The SY88713V low-power limiting post amplifier operates
from a single +3.3V or +5V power supply, over temperatures
from –40°C to +85°C. Signals with data rates up to 622Mbps
and as small as 5mVp-p can be amplified. Figure 1 shows
the allowed input voltage swing. The SY88713V generates
an SD output. SD
LVL
sets the sensitivity of the input
amplitude detection.
Input Amplifier/Buffer
Figure 2 shows a simplified schematic of the SY88713V's
input stage. The high sensitivity of the input amplifier allows
signals as small as 5mVp-p to be detected and amplified.
The input amplifier allows input signals as large as
1800mVp-p. Input signals are linearly amplified with a
typically 38dB differential voltage gain. Since it is a limiting
amplifier, the SY88713V outputs typically 1500mVp-p
voltage-limited waveforms for input signals that are greater
than 18mVp-p. Applications requiring the SY88713V to
operate with high-gain should have the upstream TIA placed
as close as possible to the SY88713V’s input pins to ensure
the best performance of the device.
Output Buffer
The SY88713V’s PECL output buffer is designed to drive
50Ω lines. The output buffer requires appropriate termination
for proper operation. An external 50Ω resistor to V
CC
–2V
for each output pin provides this. Figure 3 shows a simplified
schematic of the output stage and includes an appropriate
termination method.
Signal-Detect
The SY88813V generates a chatter-free PECL signal-
detect (SD) similar to the SY88713V's output buffer. SD is
used to determine that the input amplitude is large enough
to be considered a valid input. SD asserts high if the input
amplitude rises above the threshold set by SD
LVL
and
deasserts low otherwise. /EN deasserts the true output signal
without removing the input signals. Typically 4.6dB SD
hysteresis is provided to prevent chattering.
Signal-Detect Level Set
A programmable signal-detect level set pin (SD
LVL
) sets
the threshold of the input amplitude detection. Setting a
voltage on SD
LVL
between V
CC
and V
REF
sets this threshold.
If desired, a resistor divider between V
CC
and V
REF
, as
shown in Figure 4, also creates this threshold. The smaller
the voltage difference from SD
LVL
to V
CC
, the smaller the
SD sensitivity. Hence, larger input amplitude is required to
assert SD.
“Typical Operating Characteristics”
shows the
relationship between the input amplitude detection sensitivity
and the SD
LVL
voltage.
Hysteresis
The SY88713V provides typically 4.6dB SD electrical
hysteresis. By definition, a power ratio measured in dB is
10log(power ratio). Power is calculated as V
2IN
/R for an
electrical signal. Hence the same ratio can be stated as
20log(voltage ratio). While in linear mode, the electrical
voltage input changes linearly with the optical power and
hence the ratios change linearly. Therefore, the optical
hysteresis in dB is half the electrical hysteresis in dB given
in the datasheet. The SY88713V provides typically 2.3dB
SD optical hysteresis. As the SY88713V is an electrical
device, this datasheet refers to hysteresis in electrical terms.
With 6dB SD hysteresis, a voltage factor of two is required
to assert or deassert SD.
M9999-072505
hbwhelp@micrel.com or (408) 955-1690
5
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