Harris ICL232 5v powered, dual rs-232 transmitter/receiver Datasheet

ICL232
S E M I C O N D U C T O R
+5V Powered, Dual RS-232 Transmitter/Receiver
August 1997
Features
Description
• Meets All RS-232C and V.28 Specifications
The ICL232 is a dual RS-232 transmitter/receiver interface
circuit that meets all ElA RS-232C and V.28 specifications. It
requires a single +5V power supply, and features two
onboard charge pump voltage converters which generate
+10V and -10V supplies from the 5V supply.
• Requires Only Single +5V Power Supply
• Onboard Voltage Doubler/Inverter
• Low Power Consumption
• 2 Drivers
- ±9V Output Swing for +5V lnput
- 300Ω Power-off Source Impedance
- Output Current Limiting
- TTL/CMOS Compatible
- 30V/µs Maximum Slew Rate
The drivers feature true TTL/CMOS input compatibility, slewrate-limited output, and 300Ω power-off source impedance.
The receivers can handle up to +30V, and have a 3kΩ to 7kΩ
input impedance. The receivers also have hysteresis to
improve noise rejection.
Ordering Information
• 2 Receivers
- ±30V Input Voltage Range
- 3kΩ to 7kΩ Input Impedance
- 0.5V Hysteresis to Improve Noise Rejection
TEMP.
RANGE (oC)
PART NUMBER
PKG.
NO.
PACKAGE
ICL232CPE
0 to 70
16 Ld PDIP
E16.3
• All Critical Parameters are Guaranteed Over the Entire
Commercial, Industrial and Military Temperature Ranges
ICL232CBE
0 to 70
16 Ld SOIC
M16.3
Applications
ICL232lPE
-40 to 85
16 Ld PDIP
E16.3
ICL232lJE
-40 to 85
16 Ld CERDIP
F16.3
ICL232lBE
-40 to 85
16 Ld SOIC
M16.3
ICL232MJE
-55 to 125
16 Ld CERDIP
F16.3
• Any System Requiring RS-232 Communications Port
- Computer - Portable and Mainframe
- Peripheral - Printers and Terminals
- Portable Instrumentation
- Modems
• Dataloggers
Pinout
Functional Diagram
+5V
ICL232 (PDIP, CERDIP, SOIC)
TOP VIEW
C1+ 1
V+ 2
C1- 3
C2+ 4
C2- 5
1
16 VCC
1µF
15 GND
+
3
4
14 T1OUT
1µF
+
5
13 R1IN
12 R1OUT
V- 6
11 T1IN
T2OUT 7
10 T2IN
R2IN 8
+
1.0µF
9
T1IN
T2IN
C1+
C1C2+
C2-
16
VCC
2
+5V TO 10V
VOLTAGE INVERTER V+
+10V TO -10V
VOLTAGE INVERTER
T1
+5V
400kΩ
T2
14
7
12
13
R1OUT
R2OUT
1µF
T1OUT
T2OUT
R1IN
5kΩ
R1
R2OUT
1µF
V- 6
+
+5V
400kΩ
11
10
+
9
8
R2IN
5kΩ
R2
15
CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures.
Copyright
© Harris Corporation 1997
8-49
File Number
3020.5
ICL232
Absolute Maximum Ratings
Thermal Information
VCC to Ground . . . . . . . . . . . . . . . . . . . . . .(GND -0.3V) < VCC < 6V
V+ to Ground . . . . . . . . . . . . . . . . . . . . . . . (VCC -0.3V) < V+ < 12V
V- to Ground . . . . . . . . . . . . . . . . . . . . . . . -12V < V- < (GND +0.3V)
Input Voltages
T1IN , T2IN . . . . . . . . . . . . . . . . . . . . (V- -0.3V) < VIN < (V+ +0.3V)
R1IN , R2IN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±30V
Output Voltages
T1OUT , T2OUT . . . . . . . . . . . . (V- -0.3V) < VTXOUT < (V+ +0.3V)
R1OUT , R2OUT . . . . . . . . .(GND -0.3V) < VRXOUT < (VCC +0.3V)
Short Circuit Duration
T1OUT , T2OUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Continuous
R1OUT , R2OUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Continuous
Thermal Resistance (Typical, Note 1)
θJA (oC/W) θJC (oC/W)
CERDIP Package . . . . . . . . . . . . . . . .
80
18
PDIP Package . . . . . . . . . . . . . . . . . . .
100
N/A
SOIC Package . . . . . . . . . . . . . . . . . . .
100
N/A
Maximum Junction Temperature
Plastic Packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150oC
Ceramic Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175oC
Maximum Storage Temperature Range . . . . . . . . . .-65oC to 150oC
Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . . 300oC
Operating Conditions
Temperature Ranges
ICL232C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0oC to 70oC
ICL232I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -40oC to 85oC
ICL232M . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -55oC to 125oC
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation
of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
NOTE:
1. θJA is measured with the component mounted on an evaluation PC board in free air.
Electrical Specifications
Test Conditions: VCC = +5V ±10%, TA = Operating Temperature Range. Test Circuit as in Figure 8
Unless Otherwise Specified
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNITS
Transmitter Output Voltage Swing, TOUT
T1OUT and T2OUT Loaded with 3kΩ
to Ground
±5
±9
±10
V
Power Supply Current, ICC
Outputs Unloaded, TA = 25oC
-
5
10
mA
TIN , Input Logic Low, VlL
-
-
0.8
V
TIN , Input Logic High, VlH
2.0
-
-
V
-
15
200
µA
-30
-
+30
V
Logic Pullup Current, IP
T1IN , T2IN = 0V
RS-232 Input Voltage Range, VIN
Receiver Input Impedance, RIN
VIN = ±3V
3.0
5.0
7.0
kΩ
Receiver Input Low Threshold, VlN (H-L)
VCC = 5V, TA = 25oC
0.8
1.2
-
V
Receiver Input High Threshold, VIN (L-H)
VCC = 5V, TA = 25oC
-
1.7
2.4
V
0.2
0.5
1.0
V
Receiver Input Hysteresis, VHYST
TTL/CMOS Receiver Output Voltage Low, VOL
IOUT = 3.2mA
-
0.1
0.4
V
TTL/CMOS Receiver Output Voltage High, VOH
IOUT = -1.0mA
3.5
4.6
-
V
Propagation Delay, tPD
RS-232 to TTL
-
0.5
-
µs
Instantaneous Slew Rate, SR
CL = 10pF, RL = 3kΩ, TA = 25oC
(Notes 2, 3)
-
-
30
V/µs
Transition Region Slew Rate, SRT
RL = 3kΩ, CL = 2500pF Measured
from +3V to -3V or -3V to +3V
-
3
-
V/µs
Output Resistance, ROUT
VCC = V+ = V- = 0V, VOUT = ±2V
300
-
-
Ω
RS-232 Output Short Circuit Current, ISC
T1OUT or T2OUT Shorted to GND
-
±10
-
mA
NOTES:
2. Guaranteed by design.
3. See Figure 4 for definition.
8-50
ICL232
Test Circuits
1 C1+
+4.5V TO
+5.5V INPUT
-
1µF
C3
+
1
C1+
2
V+
VCC 16
2 V+
VCC 16
GND 15
3 C1-
T1OUT 14
4 C2+
R1IN 13
5 C2-
R1OUT 12
+
1µF
C1
-
GND 15
3kΩ
3
1µF +
C2 -
T1OUT 14
C1-
T1 OUTPUT
RS-232
±30V INPUT
TTL/CMOS
OUTPUT
4
C2+
R1IN 13
5
C2-
R1OUT 12
6
V-
T1IN 11
TTL/CMOS
INPUT
7
T2OUT
T2IN 10
TTL/CMOS
INPUT
8
R2IN
9
TTL/CMOS
OUTPUT
1µF C4
-
+
3kΩ
T2 OUTPUT
RS-232
±30V INPUT
R2OUT
6 V-
T1IN 11
7 T2OUT
T2IN 10
8 R2IN
R2OUT 9
ROUT = VIN/I
VIN = ±2V
T2OUT
A
T1OUT
FIGURE 1. GENERAL TEST CIRCUIT
FIGURE 2. POWER-OFF SOURCE RESISTANCE
CONFIGURATION
Typical Performance Curves
10
500
9
o
450 TA = 25 C
EXTERNAL SUPPLY LOAD
400 1kΩ BETWEEN V+ + GND
OR V- + GND
350 TRANSMITTER OUTPUT
V- SUPPLY
OUTPUT VOLTAGE (|V|)
V+, V- SUPPLY IMPEDANCES (Ω)
550
OPEN CIRCUIT
300
250
GUARANTEED
OPERATING
RANGE
V+ SUPPLY
V+ (VCC = 5V)
8
V+ (VCC = 4.5V)
7
6
5
TA = 25oC
4
200
150
3
4
5
V- (VCC = 5V)
V- (VCC = 4.5V)
TRANSMITTER OUTPUTS
OPEN CIRCUIT
3
6
0
1
2
3
4
INPUT SUPPLY VOLTAGE VCC (V)
5
6
7
8
9
10
|ILOAD| (mA)
FIGURE 3. V+, V- OUTPUT IMPEDANCES vs VCC
FIGURE 4. V+, V- OUTPUT VOLTAGES vs LOAD CURRENT
Pin Descriptions
PDIP, CERDIP
SOIC
PIN NAME
1
1
C1+
DESCRIPTION
2
2
V+
3
3
C1-
External capacitor “-” for internal voltage doubler.
4
4
C2+
External capacitor “+” internal voltage inverter.
5
5
C2-
External capacitor “-” internal voltage inverter.
6
6
V-
7
7
T2OUT
External capacitor “+” for internal voltage doubler.
Internally generated +10V (typical) supply.
Internally generated -10V (typical) supply.
RS-232 Transmitter 2 output ±10V (typical).
8
8
R2IN
RS-232 Receiver 2 input, with internal 5K pulldown resistor to GND.
9
9
R2out
Receiver 2 TTL/CMOS output.
10
10
T2IN
Transmitter 2 TTL/CMOS input, with internal 400K pullup resistor to VCC .
11
11
T1IN
Transmitter 1 TTL/CMOS input, with internal 400K pullup resistor to VCC .
8-51
ICL232
Pin Descriptions
(Continued)
PDIP, CERDIP
SOIC
PIN NAME
12
12
R1OUT
13
13
R1IN
14
14
T1OUT
15
15
GND
Supply Ground.
16
16
VCC
Positive Power Supply +5V ±10%
DESCRIPTION
Receiver 1 TTL/CMOS output.
RS-232 Receiver 1 input, with internal 5K pulldown resistor to GND.
RS-232 Transmitter 1 output ±10V (typical).
VOLTAGE DOUBLER
S1
C1+
VOLTAGE INVERTER
S2
V+ = 2VCC
C2+
S5
S6
VCC
GND
+
GND
C1-
S3
+
C1
-
+
C3
VCC
+
C2
-
C4
GND
S4
C2-
S7
V- = -(V+)
S8
RC
OSCILLATOR
FIGURE 5. DUAL CHARGE PUMP
Detailed Description
The ICL232 is a dual RS-232 transmitter/receiver powered by
a single +5V power supply which meets all ElA RS232C specifications and features low power consumption. The functional
diagram illustrates the major elements of the ICL232. The circuit is divided into three sections: a voltage doubler/inverter,
dual transmitters, and dual receivers Voltage Converter.
An equivalent circuit of the dual charge pump is illustrated in
Figure 5.
The voltage quadrupler contains two charge pumps which use
two phases of an internally generated clock to generate +10V
and -10V. The nominal clock frequency is 16kHz. During
phase one of the clock, capacitor C1 is charged to VCC .
During phase two, the voltage on C1 is added to VCC ,
producing a signal across C2 equal to twice VCC . At the same
time, C3 is also charged to 2VCC , and then during phase one,
it is inverted with respect to ground to produce a signal across
C4 equal to -2VCC . The voltage converter accepts input
voltages up to 5.5V. The output impedance of the doubler (V+)
is approximately 200Ω, and the output impedance of the
inverter (V-) is approximately 450Ω . Typical graphs are
presented which show the voltage converters output vs input
voltage and output voltages vs load characteristics. The test
circuit (Figure 3) uses 1µF capacitors for C1-C4, however, the
value is not critical. Increasing the values of C1 and C2 will
lower the output impedance of the voltage doubler and
inverter, and increasing the values of the reservoir capacitors,
C3 and C4, lowers the ripple on the V+ and V- supplies.
T1IN, T2IN
90%
10%
T1OUT, T2OUT
tf
VOH
VOL
tr
(0.8) (VOH - VOL) (0.8) (VOL - VOH)
Instantaneous
=
or
Slew Rate (SR)
tr
tf
FIGURE 6. SLEW RATE DEFINITION
Transmitters
The transmitters are TTL/CMOS compatible inverters which
translate the inputs to RS-232 outputs. The input logic threshold is about 26% of VCC , or 1.3V for VCC = 5V. A logic 1 at
the input results in a voltage of between -5V and V- at the output, and a logic 0 results in a voltage between +5V and (V+
- 0.6V). Each transmitter input has an internal 400kΩ pullup
resistor so any unused input can be left unconnected and its
output remains in its low state. The output voltage swing
meets the RS-232C specification of ±5V minimum with the
worst case conditions of: both transmitters driving 3kΩ minimum load impedance, VCC = 4.5V, and maximum allowable
operating temperature. The transmitters have an internally
limited output slew rate which is less than 30V/µs. The outputs
are short circuit protected and can be shorted to ground indefinitely. The powered down output impedance is a minimum of
300Ω with ±2V applied to the outputs and VCC = 0V.
V+
VCC
400kΩ
300Ω
TXIN
TOUT
GND < TXIN < VCC
V- < VTOUT < V+
V-
FIGURE 7. TRANSMITTER
Receivers
The receiver inputs accept up to ±30V while presenting the
required 3kΩ to 7kΩ input impedance even it the power is off
(VCC = 0V). The receivers have a typical input threshold of
1.3V which is within the ±3V limits, known as the transition
region, of the RS-232 specification. The receiver output is
0V to VCC . The output will be low whenever the input is
greater than 2.4V and high whenever the input is floating or
driven between +0.8V and -30V. The receivers feature 0.5V
hysteresis to improve noise rejection.
8-52
ICL232
is generated by driving them through a 5kΩ resistor
connected to V+.
VCC
RXIN
-30V < RXIN < +30V
ROUT
5kΩ
+5V
GND
16
1
C1 +
1µF -
FIGURE 8. RECEIVER
T1IN, T2IN
OR
R1IN, R2IN
T1OUT, T2OUT
OR
R1OUT, R2OUT
- C3
+ 1µF
5kΩ
2
GND < VROUT < VCC
5kΩ
3
ICL232
6
4
C2 +
1µF VOH
TD
T1
11
tPHL + tPLH
Average Propagation Delay =
2
CTS
9
R2
1
RTS
RD (3) RECEIVE DATA
CTS (5) CLEAR TO SEND
SIGNAL GROUND (7)
-
14
T2
10
+ C2
1µF
5
T1
11
TD (2) TRANSMIT DATA
7
RTS (4) REQUEST TO SEND
13
12
RD (3) RECEIVE DATA
RD
CTS
RTS (4) REQUEST TO SEND
4
ICL232
3
9
TD (2) TRANSMIT DATA
In applications requiring four RS-232 inputs and outputs
(Figure 11), note that each circuit requires two charge pump
capacitors (C1 and C2) but can share common reservoir
capacitors (C3 and C4). The benefit of sharing common reservoir capacitors is the elimination of two capacitors and the
reduction of the charge pump source impedance which
effectively increases the output swing of the transmitters.
A simple duplex RS-232 port with CTS/RTS handshaking is
illustrated in Figure 10. Fixed output signals such as DTR
(data terminal ready) and DSRS (data signaling rate select)
INPUTS
OUTPUTS
TTL/CMOS
8
C4
1µF RS-232
INPUTS AND OUTPUTS
FIGURE 10. SIMPLE DUPLEX RS-232 PORT WITH CTS/RTS
HANDSHAKING
The ICL232 may be used for all RS-232 data terminal and
communication links. It is particularly useful in applications
where ±12V power supplies are not available for conventional RS-232 interface circuits. The applications presented
represent typical interface configurations.
TD
R1
15
Applications
7
13
FIGURE 9. PROPAGATION DELAY DEFINITION
C1 +
1µF -
14
T2
INPUTS
RTS
OUTPUTS
12
TTL/CMOS RD
tPLH
+
10
VOL
tPHL
5
R2
R1
8
CTS (5) CLEAR TO SEND
15
6
-
2
C3
+
+
C4
V- V+
2µF
6
-
2 µF
2
16
+5V
RS-232
INPUTS AND
OUTPUTS
ICL232
C1 +
1µF DTR
INPUTS
OUTPUTS
TTL/CMOS
DSRS
1
4
3
5
T1
11
14
T2
10
12
7
13
DCD
R1
9
R2
CTR (20) DATA
TERMINAL READY
DSRS (24) DATA
SIGNALING RATE
SELECT
R1
15
8
+ C2
1µF
-
DTR (20) DATA TERMINAL
READY
DSRS (24) DATA SIGNALING
RATE SELECT
DCD (8) DATA CARRIER
DETECT
R1 (22) RING INDICATOR
SIGNAL GROUND (7)
FIGURE 11. COMBINING TWO ICL232s FOR 4 PAIRS OF RS-232 INPUTS AND OUTPUTS
8-53
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