SY88933V [MICREL]
3.3V/5V 1.25Gbps PECL LOW-POWER LIMITING POST AMPLIFIER; 3.3V / 5V 1.25Gbps的PECL低功率限幅后置放大器
| 型号： | SY88933V |
| 厂家： | 
MICREL SEMICONDUCTOR |
| 描述： | 3.3V/5V 1.25Gbps PECL LOW-POWER LIMITING POST AMPLIFIER |
| 文件： | 总8页 (文件大小：65K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
3.3V/5V 1.25Gbps PECL LOW-POWER
LIMITING POST AMPLIFIER
w/TTL SIGNAL DETECT
SY88933V
Final
DESCRIPTION
FEATURES
■ Single 3.3V or 5V power supply
■ DC to 1.25Gbps operation
The SY88933V 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 SY88933V
quantizes these signals and outputs PECL level waveforms.
■ Low noise PECL data outputs
■ Chatter-free OC-TTL signal setect (SD) output with
internal 6.75kΩ pull-up resistor
■ TTL EN input
The SY88933V operates from a single +3.3V or +5V
power supply, over temperatures ranging from –40°C to
+85°C. With its wide bandwidth and high gain, signals with
data rates up to 1.25Gbps and as small as 5mVp-p can be
amplified to drive devices with PECL inputs.
■ Programmable SD level set (SD
)
LVL
■ Available in a tiny 10-pin MSOP (3mm) package
The SY88933V generates a TTL SD output. A
programmable signal-detect level set pin (SD ) sets the
LVL
sensitivity of the input amplitude detection. SD asserts high
APPLICATIONS
if the input amplitude rises above the threshold set by SD
LVL
and deasserts low otherwise. EN deasserts the true output
signal without removing the input signal. Typically 4.6dB
SD hysteresis is provided to prevent chattering.
■ 1.25Gbps Ethernet
■ 1.55Mbps and 622Mbps SONET/SDH
■ High-gain line driver and line receiver
■ 531Mbps and 1062Mbps Fibre Channel
■ Gigabit interface converter
TYPICAL APPLICATIONS CIRCUIT
VCC
SD
EN
DIN
DOUT
0.1µF
0.1µF
0.1µF
0.1µF
From
Transimpedance
Amp.
To
CDR
/DIN
/DOUT
SY88933V
SDLVL
VREF
50Ω
50Ω
Rpd
Rpd
VCC
GND
GND
0.1µF
100kΩ
For 3.3V, Rpd = 120Ω
For 5V, Rpd = 220Ω
Rev.: A
Amendment: /0
Issue Date: May 1, 2003
1
SY88933V
Micrel
PACKAGE/ORDERING INFORMATION
Ordering Information
Package
Operating
Range
Package
Marking
EN
DIN
1
2
3
4
5
10 VCC
Part Number
Type
K10-1
K10-1
K10-1
K10-1
9
8
7
6
DOUT
SY88933VKC
SY88933VKCTR(Note 1)
Commercial
Commercial
Industrial
933V
933V
933V
933V
/DIN
/DOUT
SD
VREF
SDLVL
SY88933VKI
SY88933VKITR(Note 1)
GND
Industrial
Note 1. Tape and Reel.
10-Pin MSOP (K10-1)
PIN DESCRIPTION
Pin Number
Pin Name
Type
Pin Function
1
EN
TTL Input:
Enable: Deasserts true data output when high.
Default is high.
2
3
4
5
DIN
/DIN
Data Input
Data Input
True data input.
Complementary data input.
VREF
SDLVL
Reference voltage: capacitor here to VCC helps stabilize SDLVL
Signal-Detect Level Set: a resistor from this pin to VCC sets the
.
Input
threshold for the data input amplitude at which SD will be asserted.
6
7
GND
SD
Ground
Device ground.
Open-collector
TTL output w/
internal 6.75kΩ
pull-up resistor
Signal-Detect: asserts high when the data input amplitude rises above
the threshold set by SDLVL
.
8
9
/DOUT
DOUT
VCC
PECL Output
PECL Output
Power Supply
Complementary data output.
True data output.
10
Positive power supply.
2
SY88933V
Micrel
Absolute Maximum Ratings(Note 1)
Operating Ratings(Note 2)
Supply Voltage (V ) ....................................... 0V to +7.0V
Supply Voltage (V ) .............................. +3.0V to +3.6V or
CC
CC
............................................................ +4.5V to +5.5V
Input Voltage (D , /D ) .........................................0 to V
IN
IN
CC
Ambient Temperature (T ), Note 3 ............ –40°C to +85°C
Output Current (I
)
A
OUT
Continuous .............................................................50mA Junction Temperature (T ), Note 3 .......... –40°C to +120°C
J
Surge.................................................................... 100mA
Package Thermal Resistance
MSOP
EN Voltage .............................................................0 to V
CC
(θ ) Still-Air ..................................................113°C/W
V
Current ......................................... –800µA to +500µA
JA
REF
SD
Voltage ................................................. V
to V
LVL
REF CC
Storage Temperature (T ) ....................... –55°C to +125°C
S
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.
Note 2. The data sheet limits are not guaranteed if the device is operated beyond the operating ratings.
Note 3. Commercial devices are guaranteed from 0°C to +85°C ambient temperature.
DC ELECTRICAL CHARACTERISTICS
VCC = 3.0V to 3.6V or 4.5V to 5.5V; RLOAD = 50Ω to VCC–2V; TA = –40°C to +85°C; typical values at VCC = 3.3V, TA = 25°C.
Symbol
ICC
Parameter
Condition
Min
Typ
Max
42
Units
mA
V
Power Supply Current
SDLVL Voltage
No output load
22
SDLVL
VIH
VREF
2.0
VCC
EN Input HIGH Voltage
EN Input LOW Voltage
EN Input HIGH Current
V
VIL
0.8
V
IIH
VIN = 2.7V
VIN = VCC
20
100
µA
µA
IIL
EN Input LOW Current
SD Output HIGH Level
VIN = 0.5V
–0.3
mA
VOH
VCC ≥ 3.3V
2.4
2.0
V
V
VCC < 3.3V
VOL
SD Output LOW Level
PECL Output HIGH Voltage
PECL Output LOW Voltage
Differential Output Offset
Common Mode Range
Reference Voltage
IOL = +2mA
0.5
V
V
VOH
50Ω to VCC–2V output load
50Ω to VCC–2V output load
VCC–1.085 VCC–0.955 VCC–0.880
VCC–1.830 VCC–1.705 VCC–1.555
±100
VOL
V
VOFFSET
VIHCMR
VREF
mV
V
Note 1
Note 2
GND +2.0
VCC
VCC–1.38 VCC–1.32 VCC–1.26
V
Note 1. The V
range is referenced to the most positive side of the differential input signal.
IHCMR
Note 2. The current provided into or from V
must be limited to 800µA source and 500µA sink.
REF
3
SY88933V
Micrel
AC ELECTRICAL CHARACTERISTICS
VCC = 3.0V to 3.6V or 4.5V to 5.5V; RLOAD = 50Ω to VCC–2V; TA = –40°C to +85°C; typical values at VCC = 3.3V, TA = 25°C.
Symbol
HYS
tOFF
tON
Parameter
Condition
Min
Typ
4.6
0.1
0.2
Max
Units
dB
SD Hysteresis
electrical signal
2
8
SD Release Time
0.5
0.5
µs
SD Assert Time
µs
VID
Differential Input Voltage Swing
Differential Output Voltage Swing
5
5
1800 mVp-p
VOD
V
ID ≥ 18mVp-p
1500
400
mVp-p
mVp-p
VID = 5mVp-p
VSR
SD Sensitivity Range
Differential Voltage Gain
3dB Bandwidth
50
mVp-p
dB
AV(Diff)
B–3dB
S21
38
32
1
GHz
dB
Single-Ended Small-Signal Gain
26
tr,tf
Differential Output Rise/Fall Time
(20% to 80%)
VID > 100mVp-p and 50Ω to VCC – 2V load
260
ps
TYPICAL OPERATING CHARACTERISTICS
SD Assert and Deassert
SD Assert and Deassert
Levels vs. SD
Levels vs. R
LVL
SDLVL
120
140
120
100
80
VSUP = 3.3V
VSUP = 3.3V
TA = 25°C
100
80
60
40
20
0
TA = 25°C
1.25Gbps
1.25Gbps
Pattern 223–1
Pattern 223–1
ASSERT
ASSERT
60
40
DEASSERT
20
DEASSERT
0
0
0.2 0.4 0.6 0.8
1
1.2 1.4
SD (referenced to V ) (V)
LVL
CC
R
(Ω)
SDLVL
4
SY88933V
Micrel
DETAILED DESCRIPTION
SD
and deasserts low otherwise. SD can be fed back to
The SY88933V low-power limiting post amplifier operates
from a single +3.3V or +5V power supply, over temperatures
from –40°C to +85°C. Signals with data rates up to 1.25Gbps
and as small as 5mVp-p can be amplified. Figure 1 shows
the allowed input voltage swing. The SY88933V generates
LVL
the enable (EN) input to maintain output stability under a
loss of signal condition. EN deasserts the true output signal
without removing the input signals. Typically 4.6dB SD
hysteresis is provided to prevent chattering.
an SD output. SD
amplitude detection.
sets the sensitivity of the input
LVL
Signal-Detect Level Set
A programmable SD level set pin (SD ) sets the
threshold of the input amplitude detection. Connecting an
LVL
Input Amplifier/Buffer
external resistor between V
and SD
sets the voltage
Figure 2 shows a simplified schematic of the SY88933V's
input stage. The high-sensitivity of the input amplifier allows
signals as small as 5mVp-p to be detected and amplified.
The input amplifier allows input signals as large as
1800mVp-p. Input signals are linearly amplified with a
typically 38dB differential voltage gain. Since it is a limiting
amplifier, the SY88933V outputs typically 1500mVp-p
voltage-limited waveforms for input signals that are greater
than 18mVp-p. Applications requiring the SY88933V to
operate with high-gain should have the upstream TIA placed
as close as possible to the SY88933V’s input pins to ensure
the best performance of the device.
CC
LVL
at SD . This voltages ranges from V
to V
. The
REF
LVL
CC
external resistor creates a voltage divider between V and
CC
V
as shown in Figure 5. If desired, an appropriate
REF
external voltage may be applied rather than using a resistor.
The smaller the external resistor, implying a smaller voltage
difference from SD
to V , the smaller the SD sensitivity.
LVL
CC
Hence, larger input amplitude is required to assert SD.
“Typical Operating Characteristics” shows the relationship
between the input amplitude detection sensitivity and the
SD
voltage.
LVL
Hysteresis
Output Buffer
The SY88933V provides typically 4.6dB SD electrical
hysteresis. By definition, a power ratio measured in dB is
The SY88933V’s PECL output buffer is designed to drive
50Ω lines. The output buffer requires appropriate termination
2
10log(power ratio). Power is calculated as V /R for an
IN
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 datasheet. The SY88933V provides typically 2.3dB
SD optical hysteresis. As the SY88933V is an electrical
device, this datasheet refers to hysteresis in electrical terms.
With 6dB SD hysteresis, a voltage factor of two is required
to assert or deassert SD.
for proper operation. An external 50Ω resistor to V –2V
CC
for each output pin provides this. Figure 3 shows a simplified
schematic of the output stage and includes an appropriate
termination method.
Signal-Detect
The SY88933V generates a chatter-free SD open-collector
TTL output with internal 6.75kΩ pullup resistor as shown in
Figure 4. SD is used to determine that the input amplitude
is large enough to be considered a valid input. SD asserts
high if the input amplitude rises above the threshold set by
5
SY88933V
Micrel
DATA+
2.5mV (Min.)
900mV (Max.)
VIS(mVp-p)
VID(mVp-p)
DATA—
(DATA+) — (DATA—)
5mVp-p (Min.)
1800mVp-p (Max.)
Figure 1. V and V Definitions
IS
ID
VCC
VCC
ESD
STRUCTURE
DOUT
/DOUT
DIN
/DIN
ESD
STRUCTURE
GND
GND
Figure 2. Input Structure
Figure 3. Output Structure
VCC
RSDLVL
SDLVL
VCC
6.75kΩ
3kΩ
SD
VREF
Figure 4. SD Output Structure
Figure 5. SD
Setting Circuit
LVL
6
SY88933V
Micrel
FUNCTIONAL BLOCK DIAGRAM
DOUT
DIN
Limiting
Amplifer
PECL
Buffer
/DIN
/DOUT
VREF
VCC
Enable
EN
SD
Level
Detect
GND
SDLVL
DESIGN PROCEDURE
Layout and PCB Design
The SY88933V’s 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.
Since the SY88933V is a high-frequency component,
performance can be largely determined by the board layout
and design. A common problem with high-gain amplifiers is
the feedback from the large swing outputs to the input via
the power supply.
7
SY88933V
Micrel
10 LEAD MSOP (K10-1)
Rev. 00
MICREL, INC. 1849 FORTUNE DRIVE SAN JOSE, CA 95131 USA
TEL + 1 (408) 944-0800 FAX + 1 (408) 944-0970 WEB 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.
© 2003 Micrel, Incorporated.
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