MICREL SY88973VEY

Micrel, Inc.
3.3V/5V 3.2Gbps CML
LOW-POWER LIMITING
POST AMPLIFIER W/TTL LOS
SY88973V
SY88973V
DESCRIPTION
FEATURES
■ Multi-rate up to 3.2Gbps operation
■ Wide gain-bandwidth product
• 38dB differential gain
• 2GHz 3dB bandwidth
■ Low noise 50Ω CML data outputs
• 800mVPP output swing
• 60ps edge rates
• 5psRMS typ. random jitter
• 15psPP typ. deterministic jitter
■ Chatter-free, Loss-of-Signal (LOS) output
• 4.6dB electrical hysteresis
• OC-TTL output with internal 4.75kΩ pull-up
resistor
■ Programmable LOS sensitivity using single external
resistor
■ Internal 50Ω data input termination
■ TTL /EN input allows feedback from LOS
■ Wide operating range
• Single 3.3V ±10% or 5V ±10% power supply
• –40°C to +85°C industrial temperature range
■ Available in tiny 10-pin EPAD-MSOP and
16-pin MLF™ packages
The SY88973V 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 SY88973V
quantizes these signals and outputs typically 800mVPP
voltage-limited waveforms.
The SY88973V operates from a single +3.3V ±10% or
+5V ±10% power supply, over an industrial temperature
range of –40°C to +85°C. With its wide bandwidth and high
gain, signals with data rates up to 3.2Gbps and as small as
10mVPP can be amplified to drive devices with CML inputs
or AC-coupled PECL inputs.
The SY88973V incorporates a loss-of-signal (LOS), opencollector TTL output with internal 4.75kΩ pull-up resistor. A
programmable, loss-of-signal level set pin (LOSLVL) sets
the sensitivity of the input amplitude detection. LOS asserts
high if the input amplitude falls below the threshold set by
LOSLVL and de-asserts low otherwise. LOS can be fed
back to the enable (/EN) input to maintain output stability
under a loss-of-signal condition. /EN de-asserts the true
output signal without removing the input signal. Typically
4.6dB LOS hysteresis is provided to prevent chattering.
Please see Micrel’s website at www.micrel.com for a
complete selection of optical module ICs. The following table
summarizes the differences between devices in Micrel’s
latest family of Limiting Amplifiers.
All support documentation can be found on Micrel’s web
site at www.micrel.com.
Part Number
Integrated 50Ω
Input Termination
LOS
or SD
Active LOW
or HIGH Enable
SY88773V
No
LOS
LOW
SY88823V
No
SD
HIGH
APPLICATIONS
■ 1.25Gbps and 2.5Gbps Gigabit Ethernet
■ 1.062Mbps and 2.125Gbps Fibre Channel
■ 155Mbps, 622Gbps, 1.25Gbps, and 2.5Gbps SONET/
SDH
■ Gigabit interface converter (GBIC)
■ Small form factor (SFF) and small form factor
pluggable (SFP) transceivers
■ Parallel 10G Ethernet
■ High-gain line driver and line receiver
SY88843V
Yes
SD
HIGH
SY88973V
Yes
LOS
LOW
Table 1. Limiting Amplifiers Selection Guide
TYPICAL PERFORMANCE
Output Swing
(75mV/div.)
3.3V, 25°C, 10mVpp Input
@3.2Gbps 231–1 PRBS, RLOAD = 50Ω to VCC
TIME (50ps/div.)
MicroLeadFrame and MLF are trademarks of Amkor Technology, Inc.
M9999-110905
[email protected] or (408) 955-1690
Rev.: C
1
Amendment: /0
Issue Date: November 2005
SY88973V
Micrel, Inc.
FUNCTIONAL BLOCK DIAGRAM
VCC
DOUT
DIN
50Ω
Limiting
Amplifer
CML
Buffer
/DOUT
/DIN
REF
TTL
Buffer
REF
Generator
VCC
25kΩ
Level
Detect
2.8kΩ
VCC
4.75kΩ
OC-TTL
Buffer
LOSLVL
GND
M9999-110905
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/EN
2
LOS
SY88973V
Micrel, Inc.
DIN
VCC
/EN
LOSLVL
VCC
PACKAGE/ORDERING INFORMATION
16
15
14
13
1
Ordering Information(1)
12
/DOUT
Part Number
Package
Type
Operating
Range
Package
Marking
Lead
Finish
SY88973VKI
K10-2
Industrial
973V
Sn-Pb
SY88973VKITR(2)
K10-2
Industrial
973V
Sn-Pb
GND
2
11
GND
GND
3
10
GND
SY88973VMI
MLF-16
Industrial
973V
Sn-Pb
/DOUT
SY88973VMITR(2)
MLF-16
Industrial
973V
Sn-Pb
SY88973VEY(3)
K10-2
Industrial
973V with
Pb-Free bar-line indicator
Pb-Free
Matte-Sn
SY88973VEYTR(2, 3)
K10-2
Industrial
973V with
Pb-Free bar-line indicator
Pb-Free
Matte-Sn
SY88973VMG(3)
MLF-16
Industrial
973V with
Pb-Free bar-line indicator
Pb-Free
NiPdAu
SY88973VMGTR(2, 3)
MLF-16
Industrial
973V with
Pb-Free bar-line indicator
Pb-Free
NiPdAu
/DIN
4
9
8
VCC
7
LOS
6
REF
VCC
5
16-Pin MLF™ (MLF-16)
/EN 1
10 VCC
DIN 2
9 DOUT
/DIN 3
8 /DOUT
REF 4
7 LOS
LOSLVL 5
6 GND
Notes:
1. Contact factory for die availability. Dice are guaranteed at TA = 25°C, DC Electricals only.
2. Tape and Reel.
3. Pb-Free package is recommended for new designs.
10-Pin EPAD-MSOP (K10-2)
PIN DESCRIPTION
Pin Number
(MSOP)
Pin Number
(MLF™)
Pin Name
Type
1
15
/EN
TTL Input:
Default is high.
2, 3
1, 4
DIN, /DIN
Differential
Data Input
4
6
REF
5
14
LOSLVL
Input:
Default is
maximum sensitivity.
6
Exposed Pad
2, 3, 10, 11
Exposed Pad
GND
Ground
7
7
LOS
Open Collector
TTL Output with
internal 4.75kΩ
pull-up resistor
8, 9
9, 12
DOUT, /DOUT
Differential
CML Output
10
5, 8, 13, 16
VCC
Power Supply
M9999-110905
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Pin Function
Enable: De-asserts true data output when high.
Incorporates 25kΩ pull-up to VCC.
Differential data input. Each pin internally terminates to
REF through 50Ω.
Reference Voltage: Bypass with 0.01µF low ESR capacitor
from REF to VCC to stabilize LOSLVL and REF.
Loss-of-Signal level set: A resistor from this pin to VCC
sets the threshold for the data input amplitude at which the
LOS output will be asserted.
Device ground. Exposed pad must be soldered
(or equivalent) to the same potential as the ground pins.
Loss-of-Signal: asserts high when the data input amplitude
falls below the threshold set by LOSLVL.
Differential data output.
3
Positive power supply. Bypass with 0.1µF0.01µF low
ESR capacitors. 0.01µF capacitors should be as close as
possible to VCC pins.
SY88973V
Micrel, Inc.
Absolute Maximum Ratings(1)
Operating Ratings(2)
Supply Voltage (VCC) ....................................... 0V to +7.0V
/EN, LOSLVL Voltage ............................................0 to VCC
REF Current ............................................................... ±1mA
LOS Current ............................................................... ±5mA
DOUT, /DOUT Current ............................................. ±25mA
DIN, /DIN Current ..................................................... ±10mA
Storage Temperature (TS) ....................... –65°C to +150°C
Lead Temperature (Soldering, 20 sec.) .................... 260°C
Supply Voltage (VCC) .............................. +3.0V to +3.6V or
............................................................ +4.5V to +5.5V
Ambient Temperature (TA) ......................... –40°C to +85°C
Junction Temperature (TJ) ....................... –40°C to +120°C
Package Thermal Resistance(3)
MLF™
θJA (Still-Air) ..................................................... 61°C/W
ψJB ................................................................................... 38°C/W
EPAD-MSOP
θJA (Still-Air) ..................................................... 38°C/W
ψJB ................................................................................... 22°C/W
DC ELECTRICAL CHARACTERISTICS
VCC = 3.0V to 3.6V or 4.5V to 5.5V, TA = –40°C to +85°C; typical values at VCC = 3.3V, TA = 25°C.
Symbol
Parameter
Condition
ICC
Power Supply Current
Power Supply Current
Min
Typ
Max
Units
3.3V, Note 4
5V, Note 4
28
30
42
45
mA
mA
3.3V, Note 5
5V, Note 5
45
47
62
65
mA
mA
VREF
REF Voltage
VCC–1.3
VLOSLVL
LOSLVL Voltage Range
VOH
Output HIGH Voltage
Note 6
VCC–0.020 VCC–0.005
VOL
Output LOW Voltage
3.3V, Note 6
5V, Note 6
VCC–0.475 VCC–0.400 VCC–0.350
VCC–0.510 VCC–0.400 VCC–0.350
VOFFSET
Differential Output Offset
Note 6
ZO
Single-Ended Output Impedance
40
ZI
Single-Ended Input Impedance
VREF
V
VCC
V
VCC
V
V
V
±80
mV
50
60
Ω
40
50
60
Ω
Typ
Max
Units
VCC
V
0.5
V
TTL DC ELECTRICAL CHARACTERISTICS
VCC = 3.0V to 3.6V or 4.5V to 5.5V, TA = –40°C to +85°C.
Symbol
Parameter
Condition
Min
VOH
LOS Output HIGH Level
Sourcing 100µA
2.4
VOL
LOS Output LOW Level
Sinking 2mA
VIH
/EN Input HIGH Voltage
VIL
/EN Input LOW Voltage
IIH
/EN Input HIGH Current
VIN = 2.7V
VIN = VCC
IIL
/EN Input LOW Current
VIN = 0.5V
2.0
–0.3
V
0.8
V
20
100
µA
µA
mA
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 4-layer PCB. Exposed pad must be soldered (or equivalent) to the device's most negative potential on the
PCB.
4. Excludes current of CML output stage. See “Detailed Description.”
5. Total device current with no output load.
6. Output levels are based on a 50Ω to VCC load impedance. If the load impedance is different, the output level will be changed. Amplifier is in limiting
mode.
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SY88973V
Micrel, Inc.
AC ELECTRICAL CHARACTERISTICS
VCC = 3.0V to 3.6V or 4.5V to 5.5V, TA = –40°C to +85°C, RLOAD = 50Ω to VCC; typical values at VCC = 3.3V, TA = 25°C.
Symbol
Parameter
Condition
Min
Typ
PSRR
Power Supply Rejection Ratio
tr,tf
Output Rise/Fall Time
(20% to 80%)
Note 7
60
tJITTER
Deterministic
Random
Note 8
15
5
VID
Differential Input Voltage Swing
VOD
Differential Output Voltage Swing
3.3V, Note 7
5V, Note 7
HYS
LOS Hysteresis
Note 9
tOFF
Max
35
10
Units
dB
120
ps
psPP
psRMS
1800
mVPP
700
700
800
800
950
1020
mVPP
mVPP
2
4.6
8
dB
LOS Release Time
0.1
0.5
µs
tON
LOS Assert Time
0.2
0.5
µs
VSR
LOS Sensitivity Range
35
mVPP
B–3dB
–3dB Bandwidth
AV(Diff)
Differential Voltage Gain
S21
Single-Ended Small-Signal Gain
Note 10
10
2.0
GHz
32
38
dB
26
32
dB
Notes:
7. Amplifier in limiting mode. Input is a 200MHz square wave, tr < 300ps.
8. Deterministic jitter measured using 2.488Gbps K28.5 pattern, VID = 10mVPP. Random jitter measured using 2.488Gbps K28.7 pattern, VID = 10mVPP.
9. Electrical signal.
10. This is the detectable range of input amplitudes that can assert LOS. The input amplitude to deassert LOS is 2–8dB higher than the assert amplitude. See “Typical Operating Characteristics” for graphs showing how to choose a particular VLOSLVL or RLOSLVL for a particular LOS assert, and its
associated de-assert, amplitude. If increased LOS sensitivity and hysteresis are required, an application note entitled “Notes on Sensitivity and
Hysteresis in Micrel Post Amplifiers” is available at http://www.micrel.com/product-info/app_hints+notes.shtml.
M9999-110905
[email protected] or (408) 955-1690
5
SY88973V
Micrel, Inc.
TYPICAL OPERATING CHARACTERISTICS
VCC = 3.3V, TA = 25°C, RLOAD = 50Ω to VCC, unless otherwise stated.
Output Swing
(75mV/div.)
1.8Vpp Input @3.2Gbps 231–1 PRBS
Output Swing
(75mV/div.)
10mVpp Input @3.2Gbps 231–1 PRBS
TIME (50ps/div.)
TIME (50ps/div.)
VID to Assert/De-assert LOS
vs. VLOSLVL
100
100
VID to Assert/De-assert LOS
vs. RLOSLVL
40
Single-Ended Small-Signal
Gain vs. Frequency
35
10
S21 (dB)
VID (mVpp)
VID (mVpp)
30
10
25
20
15
10
5
0
60
0.2
0.4
0.6 0.8 1.0
VCC – VLOSLVL (V)
1
0.1
1.2
Power Supply Current
vs. Temperature
900
50
VOD (mVpp)
CURRENT (mA)
55
45
40
35
30
25
-40
-15
10
35
60
TEMPERATURE (°C)
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85
1
10
RLOSLVL(kΩ)
Differential Output Voltage
Swing vs. Temperature
(Amplifier in Limiting Mode)
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
FREQUENCY (GHz)
Differential Output Voltage Swing
vs. Differential Input Voltage Swing
900
880
860
840
820
800
700
800
780
760
740
720
700
-40
0
100
VOD (mVpp)
1
600
500
400
300
200
100
-15
10
35
60
TEMPERATURE (°C)
6
85
0
0 5 10 15 20 25 30 35 40 45 50
VID (mVpp)
SY88973V
Micrel, Inc.
DETAILED DESCRIPTION
Loss-of-Signal Level Set
A programmable, loss-of-signal level set pin sets the
threshold of the input amplitude detection. Connecting an
external resistor between VCC and LOSLVL sets the voltage
at LOSLVL. This voltage ranges from VCC to VREF. The
external resistor creates a voltage divider between VCC
and REF as shown in Figure 6. If desired, an appropriate
external voltage may be applied rather than using a resistor.
The relationship between VLOSLVL and RLOSLVL is given by:
The SY88973V low-power, limiting post amplifier operates
from a single +3.3V ±10% or +5V ±10% power supply, over
an industrial temperature range of –40°C to +85°C. Signals
with data rates up to 3.2Gbps and as small as 10mVPP can
be amplified. Figure 1 shows the allowed input voltage swing.
The SY88973V generates an LOS output, providing
feedback to /EN for output stability. LOSLVL sets the
sensitivity of the input amplitude detection.
Input Amplifier/Buffer
The SY88973V’s inputs are internally terminated with 50Ω
to REF. Unless unaffected by this internal termination
scheme, upstream devices need to be AC-coupled to the
SY88973V’s inputs. Figure 2 shows a simplified schematic
of the input structure.
The high sensitivity of the input amplifier detects and
amplifies signals as small as 10mVPP. The input amplifier
allows input signals as large as 1800mVPP. Input signals
are linearly amplified with a typical 38dB differential voltage
gain. Since it is a limiting amplifier, the SY88973V outputs,
typically 800mVPP, voltage-limited waveforms for input
signals that are greater than 10mVPP. Applications requiring
the SY88973V to operate with high gain should have the
upstream TIA placed as close as possible to the SY88973V’s
input pins to ensure the device’s best performance.
Output Buffer
The SY88973V’s CML output buffer is designed to drive
50Ω lines. The output buffer requires appropriate termination
for proper operation. An external 50Ω resistor to VCC or
equivalent for each output pin provides this. Figure 3 shows
a simplified schematic of the output structure and includes
an appropriate termination method. Of course, driving a
downstream device with a CML input that is internally
terminated with 50Ω to VCC eliminates the need for external
termination. As noted in the previous section, the amplifier
outputs, typically 800mVPP, waveforms across 25Ω total
loads. The output buffer, thus, switches typically 16mA tailcurrent. Figure 4 shows the power supply current
measurement which excludes the 16mA tail-current.
Loss-of-Signal
The SY88973V incorporates a chatter-free, LOS opencollector TTL output with internal 4.75kΩ pull-up resistor as
shown in Figure 5. LOS is used to determine that the input
amplitude is too small to be considered a valid input. LOS
asserts high if the input amplitude falls below the threshold
set by LOSLVL and de-asserts low otherwise. LOS can be
fed back to the enable (/EN) input to maintain output stability
under a loss of signal condition. /EN de-assert low the true
output signal without removing the input signals. Typically
4.6dB LOS hysteresis is provided to prevent chattering.
M9999-110905
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VLOSLVL = VCC – 1.3
RLOSLVL
RLOSLVL + 2.8
where voltages are in volts and resistances are in kΩ.
The smaller the external resistor, which implies a smaller
voltage difference from LOSLVL to VCC, the lower the LOS
sensitivity. Hence, larger input amplitude is required to
deassert LOS. The “Typical Operating Characteristics”
section contains graphs showing the relationship between
the input amplitude detection sensitivity and VLOSLVL or
RLOSLVL.
Hysteresis
The SY88973V provides typically 4.6dB LOS electrical
hysteresis. By definition, a power ratio measured in dB is
10log(power ratio). Power is calculated as V2IN/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
the ratios change linearly as well. Therefore, the optical
hysteresis in dB is half the electrical hysteresis in dB given
in the datasheet. The SY88973V provides typically 2.3dB
LOS optical hysteresis. As the SY88973V is an electrical
device, this datasheet refers to hysteresis in electrical terms.
With 4.6dB LOS hysteresis, a voltage factor of 1.7 is required
to deassert LOS.
Hysteresis and Sensitivity Improvement
If increased LOS sensitivity and hysteresis are required,
an application note entitled “Notes on Sensitivity and
Hysteresis in Micrel Post Amplifiers” is available at http://
www.micrel.com/product-info/app_hints+notes.shtml.
7
SY88973V
Micrel, Inc.
DATA+
5mV (Min.)
VIS(mV)
900mV (Max.)
DATA–
(DATA+) – (DATA–)
10mVpp (Min.)
VID(mVpp)
1800mVpp (Max.)
Figure 1. VIS and VID Definition
VCC
VCC
VCC
0.1µF
REF
50Ω
VCC
50Ω
50Ω
50Ω
0.1µF
DOUT Z0 = 50Ω
/DOUT
50Ω
Z0 = 50Ω
50Ω
0.1µF
DIN
0.1µF
/DIN
16mA
AC-Coupling
Capacitors
ESD
STRUCTURE
ESD
STRUCTURE
GND
GND
Figure 3. Output Structure
Figure 2. Input Structure
VCC
VCC
ICC
16mA
4.75kΩ
LOS
50Ω
50Ω
Figure 5. LOS Output Structure
ESD
STRUCTURE
VCC
RLOSLVL
16mA
LOSLVL
2.8kΩ
REF
GND
Figure 4. Power Supply Current Measurement
M9999-110905
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Figure 6. LOSLVL Setting Circuit
8
AC-Coupling
Capacitors
SY88973V
Micrel, Inc.
TYPICAL APPLICATIONS CIRCUIT
VCC
LOS
/EN
0.1µF
DIN
From
Transimpedance
Amp.
DOUT
SY88973V
/DIN
0.1µF
LOSLVL
GND
VCC
0.1µF
To
CDR
/DOUT
REF
100kΩ
0.1µF
0.1µF
RELATED PRODUCT AND SUPPORT DOCUMENTATION
Part Number
Function
Data Sheet Link
SY88773V
3.3V/5V 3.2Gbps CML Low-Power,
Limiting Post Amplifier w/ TTL LOS
http://www.micrel.com/_PDF/HBW/sy88773v.pdf
SY88823V
3.3V/5V 3.2Gbps CML Low-Power,
Limiting Post Amplifier w/ TTL SD
http://www.micrel.com/_PDF/HBW/sy88823v.pdf
SY88843V
3.3V/5V 3.2Gbps CML Low-Power,
Limiting Post Amplifier w/ TTL SD
http://www.micrel.com/_PDF/HBW/sy88843v.pdf
SY88973V
3.3V/5V 3.2Gbps CML Low-Power,
Limiting Post Amplifier w/ TTL LOS
http://www.micrel.com/_PDF/HBW/sy88973v.pdf
Application Notes
Notes on Sensitivity and Hysteresis
in Micrel Post Amplifiers
http://www.micrel.com/product-info/app_hints+notes.shtml
M9999-110905
[email protected] or (408) 955-1690
9
SY88973V
Micrel, Inc.
10 LEAD EPAD-MSOP (K10-2)
+0.08
-0.08
+0.003
-0.003
+0.05
-0.05
+0.002
-0.002
+0.15
-0.15
+0.004
-0.004
+0.10
-0.10
+0.004
-0.004
+0.008
-0.008
+0.003
-0.003
Rev.01
+0.15
-0.15
+0.006
-0.006
M9999-110905
[email protected] or (408) 955-1690
+0.07
-0.08
+0.003
-0.003
10
SY88973V
Micrel, Inc.
16-PIN MicroLEADFRAME™ (MLF-16)
Package
EP- Exposed Pad
Die
CompSide Island
Heat Dissipation
Heat Dissipation
VEE
Heavy Copper Plane
VEE
Heavy Copper Plane
PCB Thermal Consideration for 16-Pin MLF™ Package
(Always solder, or equivalent, the exposed pad to the PCB)
Package Notes:
1. Package meets Level 2 qualification.
2. All parts are dry-packaged before shipment.
3. Exposed pads must be soldered to a ground for proper thermal management.
MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131
TEL
+ 1 (408) 944-0800
FAX
+ 1 (408) 474-1000
WEB
USA
http://www.micrel.com
The information furnished by Micrel in this datasheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its use.
Micrel reserves the right to change circuitry and specifications at any time without notification to the customer.
Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can
reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into
the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser’s
use or sale of Micrel Products for use in life support appliances, devices or systems is at Purchaser’s own risk and Purchaser agrees to fully indemnify
Micrel for any damages resulting from such use or sale.
© 2005 Micrel, Incorporated.
M9999-110905
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11