TELCOM TC232CPE

1
TC232*
*Patented
DUAL RS-232 TRANSMITTER/RECEIVER AND POWER SUPPLY
2
FEATURES
GENERAL DESCRIPTION
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The TC232 is a dual RS-232 transmitter/receiver that
complies with EIA /TIA RS-232E guidelines and is ideal for
all RS-232 communication links. This device operates from
a 5V power supply and contains two charge pump voltage
converters that produce ±10V power supplies.
The TC232 has four level translators. Two are RS-232
transmitters that convert TTL/CMOS input levels to 9V
RS-232 outputs. The other two translators are RS-232
receivers that convert RS-232 inputs to 5V TTL/CMOS
output levels. The receivers have a nominal threshold of
1.3V, a typical hysteresis of 0.5V, and can operate with
inputs up to ±30V.
Meets All RS-232 Specifications
Operates From Single 5V Power Supply
2 Drivers and 2 Receivers
On-Board Voltage Quadrupler
Input Levels ...................................................... ±30V
Output Swing With +5V Supply ........................ ±9V
Low Supply Current ........................................ 5 mA
Does not require external ±12V supplies
APPLICATIONS
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RS-232C Communication Links
Modems, peripherals, computers
Battery-powered systems
+
C1 1
+ 2
–
C1 3
+
C2 4
–
C2 5
V– 6
16 VCC
15 GND
V
T2 OUT 7
R2 IN 8
16 VCC
15 GND
V
14 T1OUT
13 R1 IN
TC232CPE
TC232EPE
TC232IJE
TC232MJE
+
C1 1
+ 2
–
C1 3
+
C2 4
–
C2 5
V– 6
12 R1OUT
11 T1 IN
14 T1OUT
13 R1 IN
TC232COE
TC232EOE
T2 OUT 7
10 T2 IN
9 R2 OUT
4
ORDERING INFORMATION
PIN CONFIGURATIONS (DIP AND SOIC)
12 R1OUT
11 T1 IN
10 T2 IN
R2 IN 8
9 R2 OUT
Part No.
Package
TC232COE
TC232CPE
TC232EOE
TC232EPE
TC232IJE
TC232MJE
16-Pin SOIC (Wide)
16-Pin Plastic DIP
16-Pin SOIC (Wide)
16-Pin Plastic DIP
16-Pin CerDIP
16-Pin CerDIP
3
Temp. Range
0°C to +70°C
0°C to +70°C
– 40°C to +85°C
– 40°C to +85°C
– 25°C to +85°C
– 55°C to +125°C
5
TYPICAL APPLICATION
+5V INPUT
C3*
10 µF
+
+
10 µF
6
16
1
C1 +
10 µF
C2 +
10 µF
+
C1
3 –
C1
4 +
C2
5 –
C2
VCC
+5V TO +10V
VOLTAGE DOUBLER
V+
V–
+10V TO –10V
VOLTAGE INVERTER
2
+10V
–10V
6
+5V
+
+
C3*
10 µF
C4
10 µF
400 kΩ
11 T1IN
+5V
TTL/CMOS
INPUTS
T1OUT 14
T1
RS-232
OUTPUTS
400 kΩ
10 T2IN
12 R1OUT
T2
R1IN 13
R1
5 kΩ
TTL/CMOS
OUTPUTS
9 R2OUT
7
T2OUT 7
RS-232
INPUTS
R2IN 8
R2
5 kΩ
8
GND
*NOTE: C3 can be connected between
V+ and VCC for convenience.
15
TC232-6 10/21/96
TELCOM SEMICONDUCTOR, INC.
6-3
DUAL RS-232 TRANSMITTER/
RECEIVER AND POWER SUPPLY
TC232
ABSOLUTE MAXIMUM RATINGS*
VCC ............................................................................. +6V
V+ ........................................................................... +12V
V– ........................................................................... +12V
Input Voltages
T1IN, T2IN .................................... –0.3 to (VCC +0.3V)
R1IN, R2IN ......................................................... ±30V
Output Voltages
T1OUT, T2OUT ...................... (V+ +0.3V) to (V– –0.3V)
R1OUT, R2OUT .............................. –0.3 to (VCC +0.3V)
Short Circuit Duration
V+ .................................................................... 30sec
V– .................................................................... 30sec
T1OUT, T2OUT .......................................... Continuous
Storage Temperature Range .................. -65°C to +150°C
Package Power Dissipation (TA ≤ 70°C)
CerDIP ............................................................890mW
Derate 9.5 mW/°C Above +70°C
Plastic DIP ...................................................... 840mW
Derate 7 mW/°C Above +70°C
Small Outline (SOIC) ...................................... 760mW
Derate 7 mW/°C Above +70°C
*Static-sensitive device. Unused devices must be stored in conductive
material. Protect devices from static discharge and static fields. Stresses
above those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only and functional
operation of the device at these or any other conditions above those
indicated in the operation sections of the specifications is not implied.
Exposure to absolute maximum rating conditions for extended periods may
affect device reliability.
ELECTRICAL CHARACTERISTICS: VCC = 5V ±10%, TA = operating temperature range, test circuit unless
otherwise noted.
Parameter
Test Conditions
Output Voltage Swing
T1OUT, T2OUT Loaded With
3 kΩ to Ground
Power Supply Current
Input Logic Threshold Low
Input Logic Threshold High
Logic Pull-Up Current
RS-232 Input Voltage Operating Range
RS-232 Input Threshold Low
RS-232 Input Threshold High
RS-232 Input Hysteresis
RS-232 Input Resistance
TTL/CMOS Output Voltage Low
TTL/CMOS Output Voltage High
Propagation Delay
Instantaneous Slew Rate
Transition Region Slew Rate
Output Resistance
RS-232 Output
Short-Circuit Current
T1IN, T2IN
T1IN, T2IN
T1IN, T2IN = 0V
VCC = 5V
VCC = 5V
TA = +25°C, VCC = 5V
IOUT = 3.2 mA
IOUT = – 1 mA
RS-232 to TTL or TTL to RS-232
CL = 10 pF, RL = 3 kΩ to 7 kΩ,
TA = +25°C (Note 1)
RL = 3 kΩ, CL = 2500 pF
Measured From +3V to – 3V
or –3V to +3V
VCC = V+ = V– = 0V, VOUT = ±2V
Min
Typ
Max
Unit
±5
±9
±10
V
—
—
2
—
– 30
0.8
—
0.2
3
—
3.5
—
—
5
—
—
15
—
1.2
1.7
0.5
5
—
—
0.5
—
10
0.8
—
200
+30
—
2.4
1
7
0.4
—
—
30
mA
V
V
µA
V
V
V
V
kΩ
V
V
µsec
V/µsec
—
3
—
V/µsec
300
—
—
±10
—
—
Ω
mA
NOTE 1. Sample tested.
6-4
TELCOM SEMICONDUCTOR, INC.
DUAL RS-232 TRANSMITTER/
RECEIVER AND POWER SUPPLY
1
TC232
DETAILED DESCRIPTION
V+, V– Output Voltages vs Load Current
The TC232 contains a +5V to ±10V dual charge pump
voltage converter, a dual transmitter and a dual receiver.
10
9
Dual Transmitter
TC232 transmitters are CMOS inverters driven by ±10V
internally-generated voltages. The input is TTL/CMOS compatible, with a logic threshold of about 26% of VCC (1.3V for
5V VCC). The input of an unused transmitter can be left
unconnected, since an internal 400 kΩ pull-up resistor
connected between the transmitter input and VCC pulls the
input HIGH and forces the unused transmitter output to the
LOW state.
With VCC at 5V, the outputs will go from (V+ – 0.6V) to
V– with no load and will swing ±9V when loaded with 3 kΩ.
The minimum output voltage swing, with VCC at 4.5V and at
maximum ambient temperature, is ±5V. This conforms to
RS-232 specifications for "worst-case" conditions.
EIA/TIA RS-232E specs limit the slew rate at output
to less than 30V/µs.
The powered-down output impedance (VCC = 0V) is
a minimum of 300Ω with ±2V applied to outputs.
TELCOM SEMICONDUCTOR, INC.
OUTPUT VOLTAGE (|V|)
+5V to ±10V Dual Charge Pump
Voltage Converter
The TC232 power supply consists of two charge pumps.
One uses external capacitor C1 to double the +5V input to
+10V, with output impedance of about 200Ω. The other
uses C2 to invert +10V to – 10V, with overall output
impedance of 450Ω (including effects of +5V to +10V
doubler impedance).
The clock in the doubler circuit will start at ≈4.2V in the
typical part, but external loads may make this point rise to as
high as 4.5V with a load of 2 kΩ on each of the two output
voltages.
Because of this, use of the doubler and inverter to run
additional external circuits should be limited. The maximum
current should be no more than 2.5 mA from the +10V and
- 10V. in order to guarantee start-up of the doubler clock.
The test circuit employs 22 µF capacitors for C1 to C4,
but the value is not critical. These capacitors usually are lowcost aluminum or tantalum electrolytic capacitors.
Increasing C1 and C2 to 47 µF lowers the output
impedance of the +10V doubler and the - 10V inverter by
the change in the ESR of the capacitors.
Increasing C3 and C4 lowers ripple on the ±10V outputs and 16 kHz ripple on the RS-232 outputs. Where size
is critical, the value of C1 to C4 can be lowered to 1 µF. The
use of a low ESR capacitor will help lower the output ripple
and keep the output impedance of the ±10V as low as
possible.
V+
(VCC = 4.5V)
8
7
V–
(VCC = 4.5V)
6
2
V+
(VCC = 5V)
V–
(VCC = 5V)
3
5
CONDITIONS:
4 A) TA = +25°C
B) TRANSMITTER OUTPUTS
OPEN CIRCUIT
3
0
1 2 3 4 5 6 7 8
|I
| (mA)
LOAD
9
10
4
The outputs are protected and can be short-circuited to
ground indefinitely.
Dual Receiver
TC232 receivers meet RS-232 input specifications.
Input impedance is between 3 kΩ and 7 kΩ. Switching
thresholds are within the ±3V limits, and the receivers
withstand up to ±30V inputs. RS-232 and TTL/CMOS input
compatible, the receivers have 0.8V VIL and 2.4V VIH with
0.5V hysteresis to reject noise.
The TTL/CMOS compatible receiver output is LOW
when an RS-232 input is greater than 2.4V. It is HIGH
when an input is floating or between +0.8V and – 30V.
6
TEST CIRCUIT
+4.5V TO +5.5V
INPUT
TC232
C1 +
22 µF
22 µF
+
1
+
C1
V CC 16
2
V+
GND 15
3
–
C1
T1OUT 14
4
+
C2
R1IN 13
5
–
C2
R1OUT 12
6
V–
T1 IN 11
TTL/CMOS INPUT
7
T2 OUT
T2 IN 10
TTL/CMOS
INPUT
8
R2 IN
C3
C2
22 µF
+
+
C4
3 kΩ
22 µF
RS-232
OUTPUT
5
3 kΩ
R2OUT
9
RS-232
OUTPUT
RS-232
INPUT ±30V
7
TTL/CMOS OUTPUT
TTL/CMOS OUTPUT
RS-232
INPUT
±30V
8
6-5