ETC SY88913VKC

5V/3.3V 1.25Gbps HIGH-SPEED
LIMITING POST AMPLIFIER
FEATURES
DESCRIPTION
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3.3V and 5V power supply options
Up to 1.5Gbps operation
Low power
Low noise
Chatter-Free /LOS Generation
PECL /LOS Output
TTL /EN Input
Differential PECL inputs for data
/EN input is TTL with internal 27K pull up
Single power supply
Designed for use with Micrel-Synergy laser diode
driver and controller
■ Available in a tiny 10-pin (3mm) MSOP
The SY88913V limiting post amplifier with its high gain
and wide bandwidth is ideal for use as a post amplifier in
fiber-optic receivers with data rates up to 1.5Gbps.
Signals as small as 5mVp-p can be amplified to drive
devices with PECL inputs. The SY88913V generates a
chatter-free PECL Loss of Signal (/LOS) output.
The SY88913V incorporates a programmble level
detect function to identify when the input signal has been
lost. This information can be fed back to the /EN input of
the device to maintain stability under loss of signal
conditions. Using LOSLVL pin the sensitivity of the level
detect can be adjusted. The LOSLVL voltage can be set
by connecting a resistor divider between VCC and VREF,
Figure 2. Figure 3 and 4 show the relationship between
input level sensitivity and the voltage set on LOSLVL.
APPLICATIONS
PIN CONFIGURATION
/EN 1
■
■
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■
10 VCC
DIN 2
/DIN 3
SY88913V
9 DOUT
MSOP
K10-1
8 /DOUT
VREF 4
7
/LOS
LOSLVL 5
6
GND
1.25Gbps Gigabit Ethernet
531Mbps and 1062Mbps Fibre Channel
622Mbps SONET
Gigabit Interface Converter
BLOCK DIAGRAM
DIN
DOUT
ECL
Buffer
Limiting
Amplifer
/DIN
/DOUT
VREF
Enable
/EN
VCC
Level
Detect
GND
LOS
LOSLVL
Rev.: B
1
Amendment: /0
Issue Date: August 2000
Micrel
SY88913V
PIN NAMES
Pin
GENERAL DESCRIPTION
Type
General
The SY88913V is an integrated limiting amplifier intended
for high-frequency fiber-optic applications. The circuit
connects to typical transimpedance amplifiers found within
a fiber-optics link. The linear signal output from a
transimpedance amplifier can contain significant amounts
of noise, and may vary in amplitude over time. The
SY88913V limiting amplifier quantizes the signal and outputs
a voltage-limited waveform.
The TTL /EN pin allows the user to disable the signal
without removing the input signal.
Function
DIN
Data Input
Data Input
/DIN
Data Input
Inverting Data Input
LOSLVL
Input
Loss of Signal Level Set
/EN
TTL Input
Output Enable (active Low)
/LOS
PECL Output
Loss of Signal Indicator
(active Low)
GND
Ground
Ground
DOUT
PECL Output
Data Output
/DOUT
PECL Output
Inverting Data Output
VCC
Power Supply
Positive Power Supply
VREF
Output
Reference Voltage Output
for LOS Level Set (see Fig. 2)
ABSOLUTE MAXIMUM RATINGS(1)
Symbol
Rating
Value
Unit
VCC
Power Supply Voltage
0 to +7.0
V
DIN, /DIN
Input Voltage
0 to VCC
V
DOUT, /DOUT, /LOS
Output Voltage (with 50Ω load)
VCC –2.5 to VCC +0.3
V
LOSLVL
Input Voltage
0 to VCC
V
VREF
Output Voltage
VCC –2.0 to VCC
V
TA
Operating Temperature Range
–40 to +85
°C
Tstore
Storage Temperature Range
–55 to +125
°C
NOTE:
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 RATlNG conditions for extended
periods may affect device reliability.
2
Micrel
SY88913V
DC ELECTRICAL CHARACTERISTICS
VCC = +3.3V ±10% or +5V ±10%, RLOAD = 50Ω to VCC –2V
TA = –40°C
Symbol
Parameter
TA = 0°C
TA = +25°C
TA = +85°C
Min.
Max.
Min.
Max.
Min.
Typ.
Max.
Min.
Max.
Unit
—
—
35
35
—
—
35
35
—
—
21
23
35
35
—
—
40
40
mA
ICC
Power Supply
Current(1)
5V
3.3V
IIL
/EN Input LOW Current
–0.3(5)
—
–0.3(5)
—
–0.3(5)
—
—
–0.3(5)
—
mA
IIH
/EN Input HIGH Current
—
—
20(2)
100(3)
—
—
20(2)
100(3)
—
—
—
—
20(2)
100(3)
—
—
20(2)
100(3)
µA
VCMR
Common Mode Range
Voffset
Differential Output Offset
LOSLVL
LOSLVL Level
VOH
DOUT and /DOUT
HIGH Output
VCC –1085 VCC –880 VCC –1025 VCC –880 VCC –1025 VCC –955 VCC –880 VCC –1025
VOL
GND +2.0 VCC –1.0 GND +2.0 VCC –1.0 GND +2.0
—
VCC –1.0 GND +2.0 VCC –1.0
V
—
±100
—
±100
—
±40
±100
—
±100
mV
VREF
VCC
VREF
VCC
VREF
—
VCC
VREF
VCC
V
VCC –880
mV
DOUT and /DOUT
LOW Output
VCC –1830 VCC –1555 VCC –1810 VCC –1620 VCC –1810 VCC –1705 VCC –1620 VCC –1810 VCC –1620
mV
VREF
Reference Supply(4)
VCC –1.38 VCC –1.26 VCC –1.38 VCC –1.26 VCC –1.38 VCC –1.32 VCC –1.26 VCC –1.38
VIH
/EN Input HIGH Voltage
2.0
—
2.0
—
2.0
—
—
VIL
/EN Input LOW Voltage
—
0.8
—
0.8
—
—
0.8
VCC –1.26
V
2.0
—
V
—
0.8
V
4. IREF must be limited to be within –0.8mA (source) and 0.5mA (sink).
5. VIN = 0.5V.
NOTES:
1. No Output Load.
2. VIN = 2.7V.
3. VIN = VCC.
AC ELECTRICAL CHARACTERISTICS
VCC = +3.3V ±10% or +5V ±10%, RLOAD = 50Ω to VCC –2V
TA = –40°C
Symbol
Parameter
TA = 0°C
TA = +25°C
TA = +85°C
Min.
Max.
Min.
Max.
Min.
Typ.
Max.
Min.
Max.
Unit
—
dB
PSRR
Power Supply(1)
Rejection Ratio
—
—
—
—
—
35
—
—
VID
Input Voltage Range
5
1800
5
1800
5
—
1800
5
VOD
Differential Output
Voltage Swing(2)
—
200
—
—
—
200
—
—
—
200
700
250
—
—
—
200
—
—
mV
mV
tOFFL
/LOS Release Time(3)
Minimum Input
—
0.5
—
0.5
—
0.1
0.5
—
0.5
µs
tONL
/LOS Assert Time(3)
—
0.5
—
0.5
—
0.2
0.5
—
0.5
µs
—
0.1
0.5
—
0.5
µs
Time(4)
Input referred,
55MHz
1800 mVp-p
tOFFH
/LOS Release
Maximum Input
—
0.5
—
0.5
VSR
/LOS Sensitivity Range
5
50
5
50
5
—
50
5
50
mVp-p
HYS
/LOS Hysteresis
2
8
2
8
2
4.6
8
2
8
dB
tr, tf
Output Rise/Fall Time
—
—
260
—
—
—
260
—
—
—
170
trin,tfin
260
—
—
—
260
—
ps
NOTES:
1. Input referred noise = RMS output noise/low frequency gain.
2. Input is 622MHz square wave.
Conditions
VID = 15mVp-p
VID = 5mVp-p
VID > 100mVp-p
VID < 100mVp-p
3. Input is a 200MHz square wave, tr < 300ps, 8mVp-p.
4. Input is a 200MHz square wave, tr < 300ps, 1.8Vp-p.
3
Micrel
SY88913V
APPLICATION NOTE
Output Termination
The SY88913V outputs must be terminated with a 50Ω
load to VCC –2V (or Thevenin equivalent).
The SY88913V ground pin should be connected to the
circuit board ground. Use multiple PCB vias close to the
part to connect to ground. Avoid long, inductive runs which
can degrade performance.
Layout and PCB Design
Since the SY88913V is a high-frequency component,
performance can largely be determined by board layout
and design. A common problem with high-gain amplifiers is
feedback from the large swing outputs to the input via the
power supply.
VCC
0.1µF
0.1µF
DIN+
R1
DIN–
LOSLVL
50Ω
50Ω
R2
VREF
VREF
0.1µF
Figure 1. Differential Input Configuration
Figure 2. LOSLVL Circuit
NOTES:
LOSLVL = VCC –1.32 + R2 × 1.32
R1 + R2
R1 + R2 ≥ 5kΩ
PRODUCT ORDERING CODE
4
Ordering
Code
Package
Type
Operating
Range
SY88913VKC
K10-1
Commercial
Micrel
SY88913V
PERFORMANCE CURVE
LOS Assert and Deassert
Levels vs LOSLVL
3.3V
TA = 25°C
1.25Gbps
Pattern 27-1
90
80
70
60
50
40
30
20
10
0
0
LOS Assert and Deassert
Levels vs LOSLVL
100
INPUT LEVEL (mVp-p)
INPUT LEVEL (mVp-p)
100
70
60
50
40
30
20
10
0
-0.2 -0.4 -0.6 -0.8 -1.0 -1.2
LOSLVL = VCC – V (V)
5.0V
TA = 25°C
1.25Gbps
Pattern 27-1
90
80
0
-0.2 -0.4 -0.6 -0.8 -1.0 -1.2
LOSLVL = VCC – V (V)
Figure 4. 5.0V LOS Assert and
Deassert Levels vs. LOSLVL
Figure 3. 3.3V LOS Assert and
Deassert Levels vs. LOSLVL
5
Micrel
SY88913V
10 LEAD MSOP (K10-1)
Rev. 00
MICREL-SYNERGY
TEL
+ 1 (408) 980-9191
FAX
3250 SCOTT BOULEVARD SANTA CLARA CA 95054 USA
+ 1 (408) 914-7878
WEB
http://www.synergysemi.com http://www.micrel.com
This information is believed to be accurate and reliable, however no responsibility is assumed by Micrel for its use nor for any infringement of patents or
other rights of third parties resulting from its use. No license is granted by implication or otherwise under any patent or patent right of Micrel Inc.
© 2000 Micrel Incorporated
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