SY88993ALKG [MICROCHIP]
ATM/SONET/SDH SUPPORT CIRCUIT, PDSO10;型号: | SY88993ALKG |
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8页 (文件大小:371K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
SY88993AL
3.3V 3.2Gbps High-Speed Limiting Post
Amplifier with High Input Sensitivity
General Description
Features
The SY88993AL limiting post amplifier, with its wide
bandwidth, is ideal for use as a post amplifier in fiber-optic
receivers with data rates up to 3.2Gbps. Signals as small
as 4mVPP can be amplified to drive devices with CML
inputs or AC-coupled PECL inputs. The SY88993AL
generates a chatter-free Loss-of-Signal (LOS) open
collector TTL output using an external resistor, as shown
Figure 1.
• Up to 3.2Gbps operation
• Low noise CML data outputs
• Chatter-Free LOS generation
• Open Collector TTL LOS output
• TTL /EN Input
• Differential PECL inputs for data
• Single 3.3V power supply
The SY88993AL incorporates a programmable 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.
• Available in a tiny 10-pin (3mm x 3mm) MSOP
Applications
• PON
Using LOS
pin the sensitivity of the level detect can be
LVL
• SFP/SFF/GBIC optical transceivers
• Gigabit Ethernet
adjusted. The LOS
voltage can be set by connecting a
LVL
resistor divider between V and V
, Figure 5.
CC
REF
• 1X and 2X Fibre Channel
• SONET/SDH: OC 3/12/24/48 – STM 1/4/8/16
• Line driver and line receiver
Datasheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
Markets
• FTTX
• Datacom/Telecom
Figure 1. LOS
LVL
resistor configuration
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
M9999-093008-A
September 2008
hbwhelp@micrel.com or (408) 955-1690
Micrel, Inc.
SY88993AL
Block Diagram
Detailed Description
The SY88993AL is a high-sensitivity limiting post
amplifier that operates from a single +3.3V power
supply, over temperatures from –40oC to +85oC. Signals
with data rates up to 3.2Gbps and as small as 4mVPP
can be amplified. Figure 2 shows the allowed input
voltage swing. The SY88993AL generates a LOS output.
LOSLVL sets the sensitivity of the input amplitude
detection.
resistor, as shown in Figure 1. LOS is used to determine
that the input amplitude is large enough 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 bar (/EN)
input to maintain output stability under a loss of signal
condition. /EN de-asserts the true output signal without
removing the input signals. Typically, 5.6dB LOS
hysteresis is provided to prevent chattering.
Input Amplifier/Buffer
Loss-of-Signal Level Set
Figure
3
shows
a
simplified schematic of the
SY88993AL’s input stage. The high-sensitivity of the
input amplifier allows signals as small as 4mVPP to be
detected and amplified. The input amplifier also allows
input signals as large as 1800mVPP. Input signals below
6mVpp are linearly amplified with a typical 38dB
differential voltage gain. Since it is a limiting amplifier,
the SY88993AL outputs typically 800mVPP voltage-
limited waveforms for input signals that are greater than
10mVPP. Applications requiring the SY88993AL to
operate with high-gain should have the upstream TIA
placed as close as possible to the SY88993AL’s input
pins to ensure the best performance of the device.
The SY88993AL incorporates a programmable 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 connection a resistor divider between VCC and VREF
,
Figure 5.
Hysteresis
The SY88993AL typically provides 5.6dB 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
therefore, the ratios change linearly. Thus, the optical
hysteresis in dB is half the electrical hysteresis in dB
given in the data sheet. Since the SY88993AL is an
electrical device, this data sheet refers to hysteresis in
electrical terms. With 5.6dB LOS hysteresis, a voltage
factor of about 2 is required to assert or de-assert LOS.
Output Buffer
The SY88993AL’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 for each output pin provides this. Figure 4
shows a simplified schematic of the output stage.
Loss-of-Signal
The SY88993AL generates a chatter-free LOS open-
collector TTL output which requires an external pull-up
M9999-093008-A
hbwhelp@micrel.com or (408) 955-1690
September 2008
2
Micrel, Inc.
SY88993AL
Ordering Information
Part Number
Package
Type
Operating
Range
Package Marking
Lead
Finish
SY88993ALKG
K10-1
Industrial
993L with
Pb-Free bar-line indicator
Pb-Free
NiPdAu
SY88993ALKGTR(1)
K10-1
Industrial
993L with
Pb-Free bar-line indicator
Pb-Free
NiPdAu
Note:
1. Tape and reel.
Pin Configuration
10-Pin MSOP (K10-1)
Pin Description
Pin Number
Pin Name
Pin Function
1
2
/EN
DIN
TTL (Input): Output enable (Active Low).
Data (Input): Data input.
3
/DIN
Data (Input): Complementary data input.
Output: Reference voltage output for LOS Level Set (See Figure 3).
Input: Loss-of-Signal Level Set
4
VREF
LOSLVL
GND
5
6
Ground.
7
LOS
TTL Output (Open Collector): Loss-of-Signal indicator (Active High).
CML (Output): Inverting data output.
CML (Output): Data output.
8
/DOUT
DOUT
VCC
9
10
Power Supply: Positive power supply.
M9999-093008-A
hbwhelp@micrel.com or (408) 955-1690
September 2008
3
Micrel, Inc.
SY88993AL
Absolute Maximum Ratings(1)
Operating Ratings(2)
Supply Voltage (VCC)......................................... 0V to +4.0V
Input Voltage (DIN, /DIN) ......................................0V to VCC
Lead Temperature (soldering, #sec.)......................... 260°C
Storage Temperature (Ts) ...........................–55°C to +85°C
Supply Voltage (VIN)..................................... +3.0V to +3.6V
Ambient Temperature (TA)..........................–40°C to +85°C
Junction Thermal Resistance
MSOP (θJA) ......................................................113°C/W
MSOP (ψJB) .......................................................96oC/W
DC Electrical Characteristics
VCC = +3.3V ±10%; RLOAD = 50Ω to VCC; TA = -40°C to +85°C, unless noted. Typical values at Vcc = 3.3V, TA = 25°C
Symbol
Parameter
Condition
Min
Typ
Max
55
Units
mA
µA
ICC
Power Supply Current
LOS Output Leakage
LOSLVL Level
No output load.
Vcc = 3.6V
40
IOH
100
LOSLVL
VOH
VOL
ZO
VREF
VCC–20
Vcc-350
40
VCC
V
Output HIGH Voltage
Output LOW Voltage
VCC–5
VCC–400
50
VCC
mV
mV
Ω
Note 9
Vcc-475
60
Single-Ended Output
Impedance
Note 10
VREF
Reference Voltage
VCC–1.38
GND ±2
VCC–1.32
VCC–1.26
±80
V
mV
V
VOFFSEST
VCMR
Differential Output Offset
Common Mode Range
VCC–0.2
TTL DC Electrical Characteristics
VCC = +3.3V ±10%; RLOAD = 50Ω to VCC; TA = -40°C to +85°C, unless noted.
Symbol Parameter
Condition
Min
Typ
Max
Units
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
µA
VIN = VCC
100
IIL
/EN Input LOW Current
VIN = 0.5V
-300
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.
M9999-093008-A
hbwhelp@micrel.com or (408) 955-1690
September 2008
4
Micrel, Inc.
SY88993AL
AC Electrical Characteristics
VCC = +3.3V ±10%; RLOAD = 50Ω to VCC; TA = -40°C to +85°C, unless noted.
Symbol
LOSAH
LOSDH
HYSH
LOSAM
LOSDM
HYSM
LOSAL
LOSDL
HYSL
PSRR
tOFFL
Parameter
Condition
Min
Typ
43
Max
Units
mVPP
mVPP
dB
High LOS Assert Level
High LOS De-assert Level
High LOS Hysteresis
VLOSLVL = VCC
VLOSLVL = VCC
30
83
95
8
2
5.6
31
V
LOSLVL = VCC – 400mV
LOSLVL = VCC – 400mV
Medium LOS Assert Level
Medium LOS De-assert Level
Medium LOS Hysteresis
Low LOS Assert Level
Low LOS De-assert Level
Low LOS Hysteresis
20
mVPP
mVPP
dB
V
55
65
8
2
5.6
19
V
LOSLVL = VCC – 800mV
LOSLVL = VCC – 800mV
10
mVPP
mVPP
dB
V
31
45
8
2
5.6
35
Power Supply Rejection Ratio
LOS Release Time Minimum Input
Note 4
Note 5
dB
0.1
0.1
0.2
60
0.5
0.5
0.5
120
µs
tOFFH
LOS Release Time Maximum Input Note 5
µs
tONL
LOS Assert Time
Note 5
Note 6
µs
tr, tf
Differential Output Rise/Fall Time
(20% to 80%)
Ps
VID
VOD
Input Voltage Range
4
700
4
1800
950
50
mVPP
mVPP
mVPP
DB
Differential Output Voltage Swing
LOS Sensitivity Range
Differential Voltage Gain
3dB Bandwidth
Note 7, 8, 9, 10
800
VSR
AV(Diff)
B–3dB
S21
38
2.5
32
GHz
dB
Single-Ended Small Signal-Gain
26
Notes:
4. Input referred noise = RMS output noise/low frequency gain. Input referred, 55MHz.
5. Input is a 200MHz square wave, tr < 300ps.
6. With input signal VID > 50mVPP with 50Ω load.
7. Input is a 200MHz square wave, tr < 300ps, 50Ω load.
8. VID > 10mVPP.
9. Output levels are based on 50Ω impedance. If the load impedance is different, the output level will be changed.
10. See output structure.
M9999-093008-A
hbwhelp@micrel.com or (408) 955-1690
September 2008
5
Micrel, Inc.
SY88993AL
Typical Characteristics
Functional Characteristics
M9999-093008-A
hbwhelp@micrel.com or (408) 955-1690
September 2008
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Micrel, Inc.
SY88993AL
Figure 2. VIS and VID
Figure 4. Differential Output Configuration
Figure 3. Differential Input Configuration
Notes:
1. Resistor Divider = R2/ (R1 + R2)
2. R1 + R2 ≥ 5kΩ
Figure 5. LOSLVL Circuit
M9999-093008-A
hbwhelp@micrel.com or (408) 955-1690
September 2008
7
Micrel, Inc.
SY88993AL
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.
© 2008 Micrel, Incorporated.
M9999-093008-A
hbwhelp@micrel.com or (408) 955-1690
September 2008
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