SY88147DLKG [MICROCHIP]
ATM/SONET/SDH SUPPORT CIRCUIT, PDSO10;
| 型号： | SY88147DLKG |
| 厂家： | 
MICROCHIP |
| 描述： | ATM/SONET/SDH SUPPORT CIRCUIT, PDSO10 ATM 异步传输模式 电信 光电二极管 电信集成电路 |
| 文件： | 总10页 (文件大小：306K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
SY88147DL
3.3V, 1.25Gbps PECL Limiting Post
Amplifier w/High Gain TTL Loss-of-Signal
General Description
Features
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.
• 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 4.75kΩ pull-up resistor
• TTL /EN input
• Programmable LOS level set (LOSLVL
• Available in a tiny 10-pin MSOP
The SY88147DL operates from a single +3.3V power
supply, over temperatures ranging from –40oC to +85oC.
With its wide bandwidth and high gain, signals with data
rates up to 1.25Gbps, and as small as 5mVPP, can be
amplified to drive devices with PECL inputs.
)
Applications
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 (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.
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.
• 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
All support documentation can be found on Micrel’s web
site at: www.micrel.com.
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M9999-021207-B
hbwhelp@micrel.com or (408) 955-1690
February 2007
Micrel, Inc.
SY88147DL
Typical Application Circuit
2
M9999-021207-B
hbwhelp@micrel.com or (408) 955-1690
February 2007
Micrel, Inc.
SY88147DL
Ordering Information
Part Number
Package
Type
Operating
Range
Package Marking
Lead
Finish
NiPdAu
Pb-Free
SY88147DLKG
K10-1
Industrial
Industrial
147D with Pb-Free bar line indicator
147D with Pb-Free bar line indicator
NiPdAu
Pb-Free
SY88147DLKGTR(1)
K10-1
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 25kΩ pull-up resistor
and will default to a logic HIGH state if left open.
2
3
4
DIN
Data Input
Data Input
True data input.
/DIN
Complementary data input.
VREF
Reference voltage: Placing a capacitor here to VCC helps
stabilize LOSLVL
.
5
LOSLVL
Input
Loss-of-Signal Level Set: a resistor from this pin to VCC sets the
threshold for the data input amplitude at which LOS will be
asserted.
6
7
GND,
Exposed Pad
Ground
Device ground.
LOS
Open-collector TTL
Loss-of-Signal: asserts high when the data input amplitude falls
output w/internal 4.75kΩ below the threshold sets by LOSLVL
.
pull-up resistor
8
9
/DOUT
DOUT
VCC
PECL Output
PECL Output
Power Supply
Complementary data output.
True data output.
10
Positive power supply.
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M9999-021207-B
hbwhelp@micrel.com or (408) 955-1690
February 2007
Micrel, Inc.
SY88147DL
Absolute Maximum Ratings(1)
Operating Ratings(2)
Supply Voltage (VCC)....................................... 0V to +4.0V
Input Voltage (DIN, /DIN) .......................................0 to VCC
Supply Voltage (VCC)............................. +3.0V to +3.6V
Ambient Temperature (TA) ................... –40°C to +85°C
Junction Temperature (TJ) ................. –40°C to +125°C
Junction Thermal Resistance
Output Current (IOUT
)
Continuous........................................................±50mA
Surge ..............................................................±100mA
/EN Voltage ............................................................0 to VCC
MSOP
(θJA) Still-air..........................................113°C/W
VREF Current ..........................................-800µA to +500µA
LOSLVL Voltage................................................. VREF to VCC
Lead Temperature (soldering, 20sec.)................... +260°C
Storage Temperature (Ts) .......................–65°C to +150°C
DC Electrical Characteristics
VCC = 3.0 to 3.6V; RL = 50Ω to VCC–2V; TA = –40°C to +85°C, typical values at VCC = 3.3V, TA = 25°C.
Symbol
Parameter
Condition
Min
Typ
Max
39
Units
mA
V
ICC
Power Supply Current
LOSLVL Voltage
No output load
26
LOSLVL
VOH
VREF
VCC
PECL Output HIGH Voltage
PECL Output LOW Voltage
Common Mode Range
Reference Voltage
VCC-1.085 VCC-0.955 VCC-0.880
VCC-1.850 VCC-1.705 VCC-1.555
V
VOL
V
VIHCMR
VREF
GND+2.0
VCC
V
VCC-1.48 VCC-1.32 VCC-1.16
V
TTL DC Electrical Characteristics
VCC = 3.0 to 3.6V; RL = 50Ω to VCC–2V; TA = –40°C to +85°C, typical values at VCC = 3.3V, TA = 25°C.
Symbol Parameter
Condition
Min
Typ
Max
Units
V
VIH
VIL
IIH
/EN Input HIGH Voltage
2.0
/EN Input LOW Voltage
/EN Input HIGH Current
0.8
20
V
VIN = 2.7V
µA
µA
mA
V
V
IN = VCC
100
IIL
/EN Input LOW Current
LOS Output HIGH Level
VIN = 0.5V
-0.3
2.4
2.0
VOH
VCC > 3.3V, IOH-MAX < 160µA
V
CC < 3.3V, IOH-MAX < 160µA
V
VOL
LOS Output LOW Level
IOL = +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.
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M9999-021207-B
hbwhelp@micrel.com or (408) 955-1690
February 2007
Micrel, Inc.
SY88147DL
AC Electrical Characteristics
VCC = 3.0V to 3.6V; RLOAD =50 to VCC–2V; TA = –40°C to +85°C.
Symbol
Parameter
Condition
Min
Typ
Max
Units
tr, tf
Output Rise/Fall Time
(20% to 80%)
ps
Note 4
260
tJITTER
Deterministic
Note 5
Note 6
Figure 1
15
5
psPP
psRMS
mvPP
mvPP
Random
VID
Differential Input Voltage Swing
5
1800
VOD
Differential Output Voltage
Swing
VID > 18mVPP Figure 1
1500
TOFF
LOS Release Time
2
2
10
10
µs
µs
TON
LOS Assert Time
LOSAL
LOSDL
HYSL
LOSAM
LOSDM
HYSM
LOSAH
LOSDH
HYSH
B-3dB
Low LOS Assert Level
Low LOS De-assert Level
Low LOS Hysteresis
RLOSLVL = 15kΩ, Note 8
RLOSLVL = 15kΩ, Note 8
RLOSLVL = 15kΩ, Note 7
RLOSLVL = 5kΩ, Note 8
RLOSLVL = 5kΩ, Note 8
RLOSLVL = 5kΩ, Note 7
RLOSLVL = 100Ω, Note 8
RLOSLVL = 100Ω, Note 8
RLOSLVL = 100Ω, Note 7
2.3
3.4
3.4
4.2
6.2
3.4
10.8
16.4
3.6
1
mVPP
mVPP
dB
Medium LOS Assert Level
Medium LOS De-assert Level
Medium LOS Hysteresis
High LOS Assert Level
High LOS De-assert Level
High LOS Hysteresis
mVPP
mVPP
dB
2
2
4.5
4.5
mVPP
mVPP
dB
3dB Bandwidth
GHz
dB
AV(Diff)
S21
Differential Voltage Gain
Single-ended Small-Signal Gain
42
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, VID = 10mVPP
.
6. Random jitter measured using 1.25Gbps K28.7 pattern, VID = 10mVPP
.
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 RLOSLVL for a particular LOS assert and its associated
de-assert amplitude.
5
M9999-021207-B
hbwhelp@micrel.com or (408) 955-1690
February 2007
Micrel, Inc.
SY88147DL
Typical Operating Characteristics
VCC = 3.3V, TA = 25°C, RL = 50Ω to VCC–2V, unless otherwise stated.
6
M9999-021207-B
hbwhelp@micrel.com or (408) 955-1690
February 2007
Micrel, Inc.
SY88147DL
Functional Block Diagram
Loss-of-Signal
Detailed Description
The SY88147DL generates a chatter-free loss-of-signal
(LOS) open-collector TTL output with internal 4.75kΩ
pull-up resistor as shown in Figure 4. 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 sets 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 low the true
output signal without removing the input signals.
Typically, 3.5dB LOS hysteresis is provided to prevent
chattering.
The SY88147DL high-sensitivity limiting post amplifier
operates from a single +3.3V power supply, over
temperatures from –40°C to +85°C. Signals with data
rates up to 1.25Gbps and as small as 5mVPP can be
amplified. Figure 1 shows the allowed input voltage
swing. The SY88147DL generates a LOS output,
allowing feedback to /EN for output stability. LOSLVL sets
the sensitivity of the input amplitude detection.
Input Amplifier/Buffer
Figure 2 shows a simplified schematic of the input
stage. The high-sensitivity of the input amplifier allows
signals as small as 5mVPP to be detected and amplified.
The input amplifier allows input signals as large as
1800mVPP. Input signals are linearly amplified with a
typically 42dB differential voltage gain. Since it is a
limiting amplifier, the SY88147DL outputs typically
1500mVPP voltage-limited waveforms for input signals
that are greater than 12mVpp. Applications requiring the
SY88147DL to operate with high-gain should have the
upstream TIA placed as close as possible to the
SY88147DL’s input pins to ensure the best performance
of the device.
Loss-of-Signal-Level Set
A programmable LOS level set pin (LOSLVL) 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
CC and VREF as shown in Figure 5.
.
V
Hysteresis
The SY88147DL typically provides 3.5dB 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 hence the ratios change linearly. Therefore,
the optical hysteresis in dB is half the electrical
hysteresis in dB given in the data sheet. The
SY88147DL is an electrical device; this data sheet
refers to hysteresis in electrical terms. With 3.5dB LOS
hysteresis, a voltage factor of 1.5 is required to assert or
de-assert LOS.
Output Buffer
The SY88147DL’s PECL output buffer is designed to
drive 50Ω lines. The output buffer requires appropriate
termination for proper operation. An external 50Ω
resistor to VCC–2V for each output pin provides this.
Figure 3 shows a simplified schematic of the output
stage.
7
M9999-021207-B
hbwhelp@micrel.com or (408) 955-1690
February 2007
Micrel, Inc.
SY88147DL
Figure 1. VIS and VID Definition
Figure 2. Input Structure
Figure 3. Output Structure
Figure 4. LOS Output Structure
Figure 5. LOSLVL Setting Circuit
Note: Recommended value for RLOSLVL is 15kΩ or less.
8
M9999-021207-B
hbwhelp@micrel.com or (408) 955-1690
February 2007
Micrel, Inc.
SY88147DL
Related Product and Support Documentation
Part Number
Function
Data Sheet Link
http://www.micrel.com/product-info/sy88903al.shtml
SY88903AL
3.3V/5V 1.25Gbps PECL High-Sensitivity
Limiting Post Amplifier with TTL LOS
Application Notes
Notes on Sensitivity and Hysteresis in Micrel http://www.micrel.com/product-info/app_hints+notes.shtml
Post Amplifiers
9
M9999-021207-B
hbwhelp@micrel.com or (408) 955-1690
February 2007
Micrel, Inc.
SY88147DL
Package Information
10-Pin MSOP (K10-1)
MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA
TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http://www.micrel.com
The information furnished by Micrel in this data sheet 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 a Purchaser’s own risk
and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale.
© 2005 Micrel, Incorporated.
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M9999-021207-B
hbwhelp@micrel.com or (408) 955-1690
February 2007
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