The SP320 is a complete V.35 interface transceiver offering 3 drivers and 3 receivers of V.35, and
4 drivers and 4 receivers of RS-232 (V.28). A Sipex patented charge pump allows +5V only low
power operation. RS-232 drivers and receivers are specified to operate at 120kbps, all V.35
drivers and receivers operate up to 5Mbps.
These are stress ratings only and functional operation of the device at
these ratings or any other above those indicated in the operation
sections of the specifications below is not implied. Exposure to absolute
maximum rating conditions for extended periods of time may affect
reliability.
Voltage Outputs
Differential Outputs±0.44±0.55±0.66VoltsRL=100Ω from A to B
Source Impedance50100150Ohms
Short Circuit Impedance135150165OhmsMeasured from A=B to Gnd,
Voltage Output Offset-0.6+0.6VoltsV
AC Characteristics
Transition Time40nsRise/fall time, 10% to 90%
Maximum Transmission Rate
5MbpsRL=100Ω, V
Propagation Delay
t
t
PHL
PLH
150250nsMeasured from 1.5V of V
150250nsMeasured from 1.5V of V
V.35 RECEIVER
TTL Output Levels
V
OL
V
OH
Receiver Inputs
2.4VoltsI
Differential Input
Threshold-0.3+0.3Volts
Input Impedance90100110Ohms
Short Circuit Impedance135150165OhmsMeasured from A=B to Gnd
Voltage Outputs
High Level Output+5.0+15.0VoltsRL= 3kΩ to Gnd
Low Level Output-15.0-5.0VoltsRL= 3kΩ to Gnd
Open Circuit Output-15+15VoltsRL= ∞
Short Circuit Current-100+100mARL= Gnd
Power Off Impedance300OhmsVCC= 0V; V
AC Characteristics
Slew Rate30V/µs
Maximum Transmission Rate
120kbpsRL= 3kΩ, CL= 2500pF
0.8Volts
RL= 3kΩ, CL= 50pF; From +3V to -3V
or -3V to +3V, TA = 25˚C, VCC = +5V
OUT
= ±2V
Transition Time1.56µsRise/fall time, between ±3V
RL= 3kΩ, CL= 2500pF
Propagation Delay
t
t
PHL
PLH
28µsR
28µsR
= 3kΩ, CL= 2500pF; From 1.5V
L
of T
to 50% of V
IN
= 3kΩ, CL= 2500pF; From 1.5V
L
of T
to 50% of V
IN
OUT
OUT
RS-232 RECEIVER
TTL Output Levels
V
V
OL
OH
2.4Volts
0.4Volts
Receiver Input
Input Voltage Range-15+15Volts
High Threshold1.73.0Volts
Low Threshold0.81.2Volts
Hysteresis0.20.51VoltsVCC= 5V; TA= +25˚C
Receiver Input Circuit Bias+2.0Volts
Input Impedance357kOhmsVIN= ±15V
AC Characteristics
Maximum Transmission Rate
120kbps
Propagation Delay
t
t
PHL
PLH
0.11µsFrom 50% of R
0.11µsFrom 50% of R
to 1.5V of R
IN
to 1.5V of R
IN
OUT
OUT
POWER REQUIREMENTS
No Load VCC Supply Current3570mANo load; VCC= 5.0V; TA= 25˚C
Full Load VCC Supply Current60mARS-232 drivers RL= 3kΩ to Gnd;
DC Input
V.35 drivers RL= 100Ω from A to B;
DC Input
The SP320 is a single chip +5V-only serial
transceiver that supports all the signals necessary to implement a full V.35 interface. Three
V.35 drivers and three V.35 receivers make up
the clock and data signals. Four RS-232 (V.28)
drivers and four RS-232 (V.28) receivers are
used for control line signals for the interface.
V.35 Drivers
The V.35 drivers are +5V-only, low power
voltage output transmitters. The drivers do not
require any external resistor networks, and will
meet the following requirements:
1. Source impedance in the range of 50Ω to
150Ω.
2. Resistance between short-circuited terminals
and ground is 150Ω±15Ω.
3. When terminated with a 100Ω resistive load
the terminal to terminal voltage will be 0.55
Volts ±20% so that the A terminal is positive to
the B terminal when binary 0 is transmitted, and
the conditions are reversed to transmit binary 1.
4. The arithmetic mean of the voltage of the A
terminal with respect to ground, and the B
terminal with respect to ground will not exceed
0.6 Volts when terminated as in 3 above.
The V.35 drivers can operate at data rates as
high as 5Mbps. The driver outputs are protected
against short-circuits between the A and B
outputs and short circuits to ground.
Two of the V.35 drivers, DRIN2 and DRIN3 are
equipped with enable control lines. When the
enable pins are high the driver outputs are
disabled, the output impedance of a disabled
driver will nominally be 300Ω. When the enable
pins are low, the drivers are active.
V.35 Receivers
The V.35 receivers are +5V only, low power
differential receivers which meet the following
requirements:
1. Input impedance in the range of 100Ω±10Ω.
2. Resistance to ground of 150Ω±15Ω,
measured from short-circuited terminals.
All of the V.35 receivers can operate at data
rates as high as 5Mbps. The sensitivity of the
V.35 receiver inputs is ±300mV.
RS-232 (V.28) Drivers
The RS-232 drivers are inverting transmitters,
which accept either TTL or CMOS inputs and
output the RS-232 signals with an inverted sense
relative to the input logic levels. Typically, the
RS-232 output voltage swing is ±9V with no
load, and ±5V minimum with full load. The
transmitter outputs are protected against infinite
short-circuits to ground without degradation in
reliability.
In the power off state, the output impedance of
the RS-232 drivers will be greater than 300Ω
over a ±2V range. Should the input of a driver be
left open, an internal 400kΩ pullup resistor to
VCC forces the input high, thus committing the
output to a low state. The slew rate of the
transmitter output is internally limited to a
maximum of 30V/µs in order to meet the EIA
standards. The RS-232 drivers are rated for
120kbps data rates.
RS-232 (V.28) Receivers
The RS-232 receivers convert RS-232 input
signals to inverted TTL signals. Each of the four
receivers features 500mV of hysteresis margin
to minimize the effects of noisy transmission
lines. The inputs also have a 5kΩ resistor to
ground; in an open circuit situation the input of
the receiver will be forced low, committing the
output to a logic high state. The input resistance
will maintain 3kΩ-7kΩ over a ±15V range.
The maximum operating voltage range for the
receiver is ±30V, under these conditions the
input current to the receiver must be limited to
less than 100mA. The RS-232 receivers can
operate to beyond 120kbps.
CHARGE PUMP
The charge pump is a Sipex patented design
(U.S. 5,306,954) and uses a unique approach
compared to older less-efficient designs. The
charge pump still requires four external
capacitors, but uses a four-phase voltage
shifting technique to attain symmetrical ±10V
power supplies. The capacitors can be as low
as 0.1µF with a 16 Volt rating. Polarized or
non-polarized capacitors can be used.
Figure 1a shows the waveform found on the
positive side of capacitor C2, and Figure 1b
shows the negative side of capacitor C2. There
is a free-running oscillator that controls the four
phases of the voltage shifting. A description of
each phase follows.
Phase 1
-Vss charge storage- During this phase of the
clock cycle, the positive side of capactors C1
and C2 are initially charged to +5V. C1+ is then
switched to ground and the charge in C1- is
transferred to C2-. Since C2+ is connected to
+5V, the voltage potential across capacitor C2 is
now 10V.
Phase 2
-Vss transfer- Phase two of the clock connects
the negative terminal of C2 to the Vss storage
capacitor and the positive terminal of C2 to
ground, and transfers the generated -10V to C3.
Simultaneously, the positive side of capacitor
C1 is switched to +5V and the negative side is
connected to ground.
Phase 3
-Vdd charge storage- The third phase of the
clock is identical to the first phase- the transferred charge in C1 produces -5V in the negative
terminal of C1, which is applied to the negative
side of capacitor C2. Since C2+ is at +5V, the
voltage potential across C2 is +10V.
Phase 4
-Vdd transfer- The fourth phase of the clock
connects the negative terminal of C2 to ground
and transfers the generated +10V across C2 to
C4, the Vdd storage capacitor. Again, simultaneously with this, the positive side of capacitor
C1 is switched to +5V and the negative side is
connected to ground, and the cycle begins again.
Since both V+ and V- are separately generated
from Vcc in a no load condition, V+and V- will
be symmetrical. Older charge pump approaches
that generate V- from V+ will show a decrease
in the magnitude of V- compared to V+ due to
the inherent inefficiencies in the design.
The clock rate for the charge pump typically
operates at 15kHz. The external capacitors must
be 0.1µF with a 16V breakdown rating.
Shutdown Mode
The SP320 can be put into a low power
shutdown mode by bringing both TS000 (pin 3)
and ENV35 (pin 9) low. In shutdown mode, the
SP320 will draw less than 2mA of supply
current. For normal operation, both pins should
be connected to +5V.
External Power Supplies
For applications that do not require +5V only,
external supplies can be applied at the V+ and
V- pins. The value of the external supply
voltages must be no greater than ±10V. The
current drain from the ±10V supplies is used for
the RS-232 drivers. For the RS-232 driver the
current requirement will be 3.5mA per driver.
It is critical the external power supplies provide
a power supply sequence of : +10V, +5V, and
then -10V.
Applications Information
The SP320 is a single chip device that can
implement a complete V.35 interface. Three (3)
V.35 drivers and three (3) V.35 receivers are
used for clock and data signals and four (4)
RS-232 (V.28) drivers and four (4) RS-232
(V.28) receivers can be used for the control
signals of the interface. The following examples
show the SP320 configured in either a DTE or
DCE application.
Signal GroundB
Clear to SendD
Data Carrier DetectF
Ring IndicatorJ
Local LoopbackL
Remote LoopbackN
Receive Data (A)R
Receive Data (B)T
Receive Timing (A)V
Receive Timing (B)X
Unassigned---Z
Unassigned---BB
Unassigned---DD
Unassigned---FF
Unassigned---JJ
Unassigned---LL
Test ModeNN
Signal GroundB
Clear to SendD
Data Carrier DetectF
Ring IndicatorJ
Local LoopbackL
Remote LoopbackN
Receive Data (A)R
Receive Data (B)T
Receive Timing (A)V
Receive Timing (B)X
Unassigned---Z
Unassigned---BB
Unassigned---DD
Unassigned---FF
Unassigned---JJ
Unassigned---LL
Test ModeNN
SP320ACF ...................................................0˚C to +70˚C......................... 80-pin JEDEC (BE-2 Outline) QFP
Please consult the factory for pricing and availability on a Tape-On-Reel option.
Corporation
SIGNAL PROCESSING EXCELLENCE
Sipex Corporation
Headquarters and
Sales Office
22 Linnell Circle
Billerica, MA 01821
TEL: (978) 667-8700
FAX: (978) 670-9001
e-mail: sales@sipex.com
Sales Office
233 South Hillview Drive
Milpitas, CA 95035
TEL: (408) 934-7500
FAX: (408) 935-7600
Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of the
application or use of any product or circuit described hereing; neither does it convey any license under its patent rights nor the rights of others.