SY88147DL
3.3V, 1.25Gbps PECL Limiting Post
Amplifier w/High Gain TTL Loss-of-Signal
December 2005
1
M9999-120805-A
hbwhelp@micrel.com
or (408) 955-1690
General Description
The SY88147DL is a high-sensitivity limiting post
amplifier designed for use in fiber-optic receivers. These
devices connect 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 SY88147DL quantizes these signals and
outputs PECL level waveforms.
The SY88147DL operates from a single +3.3V power
supply, over temperatures ranging from 40
o
C to +85
o
C.
With its wide bandwidth and high gain, signals with data
rates up to 1.25Gbps, and as small as 5mV
PP
, can be
amplified to drive devices with PECL inputs.
The SY88147DL generates a high-gain loss-of-signal
(LOS) open-collector TTL output. The LOS function has
a high gain input stage for increased sensitivity. A
programmable Loss-of-Signal level set pin (LOS
LVL
) sets
the sensitivity of the input amplitude detection. LOS
asserts high if the input amplitude falls below the
threshold set by LOS
LVL
and de-asserts low otherwise.
The enable bar input (/EN) de-asserts the true output
signal without removing the input signal. The LOS
output can be fed back to the /EN input to maintain
output stability under a loss-of-signal condition. Typically
3.5dB LOS hysteresis is provided to prevent chattering.
All support documentation can be found on Micrel's web
site at:
www.micrel.com
.
Features
Single 3.3V power supply
DC to 1.25Gbps operation
Low-noise PECL data outputs
High-gain LOS
Chatter-free Open-Collector TTL Loss of Signal
(LOS) output with internal 4.75k
pull-up resistor
TTL /EN input
Programmable LOS level set (LOS
LVL
)
Available in a tiny 10-pin MSOP
Applications
APON/BPON/EPON/GEPON/GPON
Gigabit Ethernet
531Mbps and 1062Mbps Fibre Channel
OC-3 and OC-12/24 SONET/SDH
High-gain line driver and line receiver
Low-gain TIA interface
Markets
FTTH
Datacom/Telecom
Optical transceiver
Micrel, Inc.
SY88147DL
December 2005
2
M9999-120805-A
hbwhelp@micrel.com
Typical Application Circuit
or (408) 955-1690
Micrel, Inc.
SY88147DL
December 2005
3
M9999-120805-A
hbwhelp@micrel.com
or (408) 955-1690
Ordering Information
Part Number
Package
Type
Operating
Range
Package Marking
Lead
Finish
SY88147DLKG
K10-1
Industrial
SY88147DL with Pb-Free bar line indicator
NiPdAu
Pb-Free
SY88147DLKGTR
(1)
K10-1
Industrial
SY88147DL with Pb-Free bar line indicator
NiPdAu
Pb-Free
Note:
1. Tape
and
Reel.
Pin Configuration
10-Pin MSOP (K10-1)
Pin Description
Pin Number
Pin Name
Type
Pin Function
1 /EN
TTL Input: Default is
HIGH.
/Enable: This input enables the outputs when it is LOW. Note
that this input is internally connected to a 25k pull-up resistor
and will default to a logic HIGH state if left open.
2
DIN
Data Input
True data input.
3
/DIN
Data Input
Complementary data input.
4 VREF
Reference voltage: Placing a capacitor here to V
CC
helps
stabilize LOS
LVL
.
5 LOSLVL
Input Loss-of-Signal Level Set: a resistor from this pin to V
CC
sets the
threshold for the data input amplitude at which LOS will be
asserted.
6
GND,
Exposed Pad
Ground Device
ground.
7 LOS
Open-collector TTL
output w/internal 4.75k
pull-up resistor
Loss-of-Signal: asserts high when the data input amplitude falls
below the threshold sets by LOS
LVL
.
8
/DOUT
PECL Output
Complementary data output.
9
DOUT
PECL Output
True data output.
10
VCC
Power Supply
Positive power supply.
Micrel, Inc.
SY88147DL
December 2005
4
M9999-120805-A
hbwhelp@micrel.com
or (408) 955-1690
Absolute Maximum Ratings
(1)
Supply Voltage (V
CC
) ....................................... 0V to +4.0V
Input Voltage (DIN, /DIN) .......................................0 to V
CC
Output Current (I
OUT
)
Continuous........................................................ 50mA
Surge ..............................................................100mA
/EN Voltage ............................................................0 to V
CC
V
REF
Current .......................................... -800A to +500A
LOS
LVL
Voltage................................................. V
REF
to V
CC
Lead Temperature (soldering, 20sec.) ................... +260C
Storage Temperature (T
s
) ....................... 65C to +150C
Operating Ratings
(2)
Supply Voltage (V
CC
)............................. +3.0V to +3.6V
Ambient Temperature (T
A
) ................... 40C to +85C
Junction Temperature (T
J
) ................. 40C to +125C
Junction Thermal Resistance
MSOP
(
JA
) Still-air.......................................... 113C/W
DC Electrical Characteristics
V
CC
= 3.0 to 3.6V; R
L
= 50 to V
CC
2V; T
A
= 40C to +85C, typical values at V
CC
= 3.3V, T
A
= 25C.
Symbol Parameter
Condition
Min
Typ Max Units
I
CC
Power Supply Current
No output load
26
39
mA
LOS
LVL
LOS
LVL
Voltage
V
REF
V
CC
V
V
OH
PECL Output HIGH Voltage
V
CC
-1.085 V
CC
-0.955 V
CC
-0.880
V
V
OL
PECL Output LOW Voltage
V
CC
-1.850 V
CC
-1.705 V
CC
-1.555
V
V
IHCMR
Common Mode Range
GND+2.0
V
CC
V
V
REF
Reference Voltage
V
CC
-1.48 V
CC
-1.32 V
CC
-1.16
V
TTL DC Electrical Characteristics
V
CC
= 3.0 to 3.6V; R
L
= 50 to V
CC
2V; T
A
= 40C to +85C, typical values at V
CC
= 3.3V, T
A
= 25C.
Symbol Parameter
Condition
Min
Typ Max Units
V
IH
/EN Input HIGH Voltage
2.0
V
V
IL
/EN Input LOW Voltage
0.8
V
I
IH
/EN Input HIGH Current
V
IN
= 2.7V
V
IN
= V
CC
20
100
A
A
I
IL
/EN Input LOW Current
V
IN
= 0.5V
-0.3
mA
V
OH
LOS Output HIGH Level
V
CC
> 3.3V, I
OH-MAX
< 160A
V
CC
< 3.3V, I
OH-MAX
< 160A
2.4
2.0
V
V
V
OL
LOS Output LOW Level
I
OL
= +2mA
0.5
V
Notes:
1. 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 rating conditions for
extended periods may affect device reliability.
2. The data sheet limits are not guaranteed if the device is operated beyond the operating ratings.
3. Thermal performance assumes the use of a 4-layer PCB. Exposed pad must be soldered (or equivalent) to the device's most negative potential
on the PCB.
Micrel, Inc.
SY88147DL
December 2005
5
M9999-120805-A
hbwhelp@micrel.com
or (408) 955-1690
AC Electrical Characteristics
V
CC
= 3.0V to 3.6V; R
LOAD
=50 to V
CC
2V; T
A
= 40C to +85C.
Symbol Parameter
Condition
Min
Typ Max Units
t
r
, t
f
Output Rise/Fall Time
(20% to 80%)
Note 4
260
ps
t
JITTER
Deterministic
Random
Note 5
Note 6
15
5
ps
PP
ps
RMS
V
ID
Differential Input Voltage Swing
Figure 1
5
1800
mv
PP
V
OD
Differential Output Voltage
Swing
V
ID
> 18mV
PP
Figure 1
1500
mv
PP
T
OFF
LOS Release Time
2 10
s
T
ON
LOS Assert Time
2 10
s
LOS
AL
Low LOS Assert Level
R
LOSLVL
= 15k
, Note 8
2.3
mV
PP
LOS
DL
Low LOS De-assert Level
R
LOSLVL
= 15k
, Note 8
3.4
mV
PP
HYS
L
Low LOS Hysteresis
R
LOSLVL
= 15k
, Note 7
3.4 dB
LOS
AM
Medium LOS Assert Level
R
LOSLVL
= 5k
, Note 8
4.2
mV
PP
LOS
DM
Medium LOS De-assert Level
R
LOSLVL
= 5k
, Note 8
6.2
mV
PP
HYS
M
Medium LOS Hysteresis
R
LOSLVL
= 5k
, Note 7
2 3.4 4.5 dB
LOS
AH
High LOS Assert Level
R
LOSLVL
= 100
, Note 8
10.8 mV
PP
LOS
DH
High LOS De-assert Level
R
LOSLVL
= 100
, Note 8
16.4 mV
PP
HYS
H
High LOS Hysteresis
R
LOSLVL
= 100
, Note 7
2 3.6 4.5 dB
B
-3dB
3dB Bandwidth
1
GHz
A
V(Diff)
Differential Voltage Gain
42
dB
S
21
Single-ended Small-Signal Gain
30
36
dB
Notes:
4. Amplifier in limiting mode. Input is a 200MHz square wave.
5. Deterministic jitter measured using 1.25Gbps K28.5 pattern, V
ID
= 10mV
PP
.
6. Random jitter measured using 1.25Gbps K28.7 pattern, V
ID
= 10mV
PP
.
7. This specification defines electrical hysteresis as 20log (LOS De-assert/LOS Assert). The ratio between optical hysteresis and electrical
hysteresis is found to vary between 1.5 and 2 depending on the level of received optical power and ROSA characteristics. Based on that ratio,
the optical hysteresis corresponding to the electrical hysteresis range 2dB-4.5dB, shown in the AC characteristics table, will be 1dB-3dB.
8. See "Typical Operating Characteristics" for a graph showing how to choose a particular R
LOSLVL
for a particular LOS assert and its associated de-
assert amplitude.
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