VITESSE
SEMICONDUCTOR CORPORATION
Preliminary Data Sheet
VSC7937
Single Supply 2.5Gb/s Voltage Driver
G52200-0, Rev 3.0
Page 1
03/05/01
VITESSE
SEMICONDUCTOR CORPORATION 741 Calle Plano Camarillo, CA 93012
Tel: (800) VITESSE FAX: (805) 987-5896 Email: prodinfo@vitesse.com
Internet: www.vitesse.com
Features
Applications
General Description
The VSC7937 is a single -5.2V supply, 2.5Gb/s voltage driver with direct access to the output modulation
and bias FETs. The output stage can drive 60mA into 50
with adequate output voltage compliance. Output
bias and modulation currents are set by external components allowing precision monitoring and setting of the
output voltage levels.
VSC7937 Block Diagram
Typical Rise Times of 100ps
High-Speed Operation
(Up to 2.5Gb/s NRZ Data)
3V Output Voltage Compliance
Single-Ended or Differential Input Operation
Single Power Supply: +5V or -5.2V
Direct Access to Modulation and Bias FETs
On-Die MUX for Clocked or Unclocked
Applications
On-Chip 50
Input Clock and Data Termination
SONET/SDH @ 622Mb/s, 1.244Gb/s, 2.488Gb/s
Full-Speed Fibre Channel (1.062Gb/s)
IBIAS1
OUT
NOUT
VIP
VIB2
VIB1
MIP
MIB1
MIB2
IMOD
IBIAS2
I
NOUT
*Terminated to Off-chip Capacitor
**On Die Components
M
U
X
SEL
DIN
DINTERM*
D Q
50
**
50
**
50
**
50
**
NDIN
CLK
NCLK
CLKTERM*
SEL
VITESSE
SEMICONDUCTOR CORPORATION
Preliminary Data Sheet
VSC7937
Single Supply 2.5Gb/s Voltage Driver
Page 2
G52200-0, Rev 3.0
03/05/01
VITESSE
SEMICONDUCTOR CORPORATION 741 Calle Plano Camarillo, CA 93012
Tel: (800) VITESSE FAX: (805) 987-5896 Email: prodinfo@vitesse.com
Internet: www.vitesse.com
Electrical Characteristics
Table 1: High-Speed Inputs and ECL Outputs
V
SS
= -5.2V, R
L
= 50
at I
OUT
pin
NOTE: (1) 100mA when R
L
= 30
at (N) OUT pin.
Table 2: DC Characteristics
Symbol
Parameter
Min
Typ
Max
Units
Conditions
V
IN
Single-Ended Input Voltage Swing
300
--
1500
mVp-p
V
CM
= -2.0V
V
CM
Differential Input Common-Mode Range
-2.3
--
-1.3
V
V
SS
= -5.2V
V
OH
ECL Output HIGH Voltage
-1200
--
--
mV
50
to -2.0V
V
OL
ECL Output LOW Voltage
--
--
-1600
mV
50
to -2.0V
V
IN
On-Chip Terminations
35
--
65
I
NOUT
Maximum Peak Current
(1)
60
--
--
mA
VIP = VSS + 1.4V
VIB1 = -5.2V
VIB2 = -5.2V
DIN = LOW
I
NOUT
Maximum Peak Current
--
--
4
mA
VIP = -4.1V
VIB1 = -5.2V
VIB2 = -5.2V
DIN = HIGH
t
R,
t
F
Rise and Fall Times
--
--
100
ps
20% to 80%
V
OUT
Output Voltage
--
--
-3.0
V
VIP = -4.1V
VIB1 = -5.2V
VIB2 = -5.2V
DIN = LOW
t
SU
Set-up Time - Data to CLK
20
50
--
ps
t
H
Hold Time
--
50
90
ps
Symbol
Parameter
Min
Typ
Max
Units
Conditions
V
SS
Power Supply Voltage
-5.5
-5.2
-4.75
V
I
BIAS1,
I
BIAS2
Maximum Bias Current
30
--
--
mA
VIB1, 2 = VSS + 1.8V
VIP = -5.2V
V
DCC
Duty-Cycle Control Voltage
V
SS
--
V
SS
+
3V
V
V
IH
HIGH Level Input Voltage
-1.15
-0.9
-0.8
V
V
REF
= 1.3V
V
IL
LOW Level Input Voltage
--
-1.7
-1.45
V
V
REF
= 1.3V
VIB1, VIB2
BIAS Control Voltage
V
SS
--
V
SS
+1.8
V
VIP
Modulation Control Voltage
V
SS
--
V
SS
+1.4
V
VITESSE
SEMICONDUCTOR CORPORATION
Preliminary Data Sheet
VSC7937
Single Supply 2.5Gb/s Voltage Driver
G52200-0, Rev 3.0
Page 3
03/05/01
VITESSE
SEMICONDUCTOR CORPORATION 741 Calle Plano Camarillo, CA 93012
Tel: (800) VITESSE FAX: (805) 987-5896 Email: prodinfo@vitesse.com
Internet: www.vitesse.com
Table 3: Power Dissipation
Table 4: Package Thermal Specifications
Table 5: MUX Select Logic Table
Absolute Maximum Ratings
(1)
Power Supply Voltage (V
SS
) ............................................................................................................. V
CC
to -6.0V
Operating Junction Temperature Range (T
J
) ............................................................................... -55C to +125C
Storage Temperature Range (T
S
)................................................................................................. -65C to +150C
NOTE: (1) CAUTION: Stresses listed under "Absolute Maximum Ratings" may be applied to devices one at a time without caus-
ing permanent damage. Functionality at or above the values listed is not implied. Exposure to these values for extended
periods may affect device reliability.
Recommended Operating Conditions
Positive Voltage Rail (GND) ..............................................................................................................................0V
Negative Voltage Rail (V
SS
) .......................................................................................................................... -5.2V
Operational Case Temperature Range (T
C
)
(1)
............................................................................... -40C to +85C
NOTE: (1) Lower limit of specification is ambient temperature and upper limit is case temperature
Symbol
Parameter
Min
Typ
Max
Units
Conditions
I
SS
Power Supply Current (V
SS
)
--
--
-
120
mA
V
SS
= -5.5V, I
MOD
=
I
BIAS
= 0mA
P
D
Total Power Dissipation
--
--
700
mW
V
SS
= -5.5V, I
MOD
=
I
BIAS
= 0 mA
Symbol
Parameter
Min
Typ
Max
Units
Conditions
JCC
Thermal Resistance from Junction to Case
--
25
--
C/W
Ceramic Package
JCP
Thermal Resistance from Junction to Case
--
15
--
C/W
Plastic Package
Symbol
Rating
VSS
Clocked Data In
GND
Non-clocked Data In
NC
Non-clocked Data In
VITESSE
SEMICONDUCTOR CORPORATION
Preliminary Data Sheet
VSC7937
Single Supply 2.5Gb/s Voltage Driver
Page 4
G52200-0, Rev 3.0
03/05/01
VITESSE
SEMICONDUCTOR CORPORATION 741 Calle Plano Camarillo, CA 93012
Tel: (800) VITESSE FAX: (805) 987-5896 Email: prodinfo@vitesse.com
Internet: www.vitesse.com
Figure 1: On-Chip Data and Clock Input Configuration
Figure 2: Single-Ended Operation
Figure 3: Single-Ended AC-Coupled
(NCLK)
NDIN
(CLKTERM)
DINTERM
(CLK)
DIN
VSS
VSS
GND
GND
50
50
4.0K
6.4K
DATA BUFFER
(CLOCK BUFFER)
X
X
X
*
*
*
*
*On-chip
Components
0.1f
0.1f
0.1f
0.1f
GND
NCLK
CLK
NDIN
DINTERM
DIN
7937
DATA
SOURCE
CLOCK
SOURCE
GND
GND
CLKTERM
GND
0.1f
0.1f
X
X
(NCLK)
NDIN
X
(CLKTERM)
DINTERM
(CLK)
DIN
VSS
GND
50
-2.0V
50
4.0K
6.4K
SOURCE
0.1
f
0.1
f
GND
0.1
f
GND
VITESSE
SEMICONDUCTOR CORPORATION
Preliminary Data Sheet
VSC7937
Single Supply 2.5Gb/s Voltage Driver
G52200-0, Rev 3.0
Page 5
03/05/01
VITESSE
SEMICONDUCTOR CORPORATION 741 Calle Plano Camarillo, CA 93012
Tel: (800) VITESSE FAX: (805) 987-5896 Email: prodinfo@vitesse.com
Internet: www.vitesse.com
Figure 4: Differential AC-Coupled
Figure 5: Differential DC-Coupled/Differential ECL
X
X
(NCLK)
NDIN
X
(CLKTERM)
DINTERM
(CLK)
DIN
VSS
GND
50
-2.0V
50
4.0K
6.4K
SOURCE
0.1
f
0.1
f
GND
0.1
f
X
X
(NCLK)
NDIN
X
(CLKTERM)
DINTERM
(CLK)
DIN
VSS
-2.0V
GND
50
-2.0V
50
4.0K
6.4K
SOURCE
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