®
SP230A/234A/235A/236A/237A/238A/241A SP235B/236B/240A/240B/241A/241B
+5V Powered Multi-Channel RS-232 Drivers/Receivers
■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Operates from Single +5V Power Supply Meets All RS-232D and V.28 Specifications ±9V Output Swing with +5V Supply Improved Driver Output Capacity for Mouse Applications Low Power Shutdown – 1µA WakeUp Feature in Shutdown Mode 3–State TTL/CMOS Receiver Outputs ±30V Receiver Input Levels Low Power CMOS – 5mA Operation Wide Charge Pump Capacitor Value Range – 1-10µF
T 1 OUT T2 OUT T2 IN T1 IN GND VCC C1+ V+
1 2 3
16 15 14
T3 OUT T 4 OUT T 4 IN T3 IN VC2 C2 + C1 -
SP234A
4 5 6 7 8
13 12 11 10 9
Now Available in Lead Free Packaging
DESCRIPTION… The SP230A Series are multi–channel RS-232 line drivers/receivers that provide a variety of configurations to fit most communication needs, especially where ±12V is not available. Some models feature a shutdown mode to conserve power in battery-powered systems. Some require no external components. All, except one model, feature a built-in charge pump voltage converter, allowing them to operate from a single +5V power supply. All drivers and receivers meet all EIA RS-232D and CCITT V.28 requirements. The Series is available in plastic DIP and SOIC packages.
SELECTION TABLE
Model SP230A SP234A SP235A SP235B SP236A SP236B SP237A SP238A SP240A SP240B SP241A SP241B Power Supplies +5V +5V +5V +5V +5V +5V +5V +5V +5V +5V +5V +5V No. of RS-232 Drivers 5 4 5 5 4 4 5 4 5 5 4 4 No. of RS-232 Rcvrs 0 0 5 5 3 3 3 4 5 5 5 5 External Low Power TTL Wake- No. of Components Shutdown 3–State Up Pins 4 Capacitors Yes No No 20 4 Capacitors No No No 16 None Yes Yes No 24 None Yes Yes Yes 24 4 Capacitors Yes Yes No 24 4 Capacitors Yes Yes Yes 24 4 Capacitors No No No 24 4 Capacitors No No No 24 4 Capacitors Yes Yes No 44 4 Capacitors Yes Yes Yes 44 4 Capacitors Yes Yes No 28 4 Capacitors Yes Yes Yes 28
Date: 8/3/04
+ 5V Powered Multi-Channel RS-232 Drivers/Receivers
© Copyright 2004 Sipex Corporation
1
ABSOLUTE MAXIMUM RATINGS
This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operation sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability. VCC ............................................................................................................................................................... +6V V+ ................................................................................................................... (Vcc–0.3V) to +13.2V V– ............................................................................................................................................................. 13.2V Input Voltages: TIN ....................................................................................................................... –0.3 to (Vcc +0.3V) RIN ............................................................................................................................................................ ±30V
Output Voltages: TOUT ................................................................................................. (V+, +0.3V) to (V–, –0.3V) ROUT .............................................................................................................. –0.3V to (Vcc +0.3V) Short Circuit Duration: TOUT ......................................................................................................................................... Continuous Power Dissipation: CERDIP .............................................................................. 675mW (derate 9.5mW/°C above +70°C) Plastic DIP .......................................................................... 375mW (derate 7mW/°C above +70°C) Small Outline ...................................................................... 375mW (derate 7mW/°C above +70°C)
ELECTRICAL CHARACTERISTICS
All units Vcc=+5V±10%; except SP235A/B, Vcc=+5V±5%; All specifications TMIN to TMAX unless otherwise noted.
PARAMETERS POWER REQUIREMENTS Vcc Power Supply Current Shutdown Supply Current LOGIC INPUTS Input Logic Threshold Low High Logic Pullup Current RS-232 INPUTS RS-232 Input Voltage Range RS-232 Input Threshold Low High RS-232 Input Hysteresis RS-232 Input Resistance LOGIC OUTPUTS Output Voltage Low High Output Leakage Current RS-232 OUTPUTS Output Enable Time Output Disable Time Propagation Delay Instantaneous Slew Rate RS-232 OUTPUTS Transition Region Slew Rate Output Voltage Swing
MIN.
TYP. 5 1
MAX. 10 10
UNITS mA µA
CONDITIONS No load, TA= +25°C TA = +25°C
0.8 2.0 15 -30 0.8 0.2 3 1.2 1.7 0.5 5 200 +30 2.4 1.0 7
Volts Volts µA Volts Volts Volts Volts kOhms
TIN ; EN, SD TIN ; EN, SD TIN = 0V
Vcc = 5V, TA = +25°C Vcc = 5V, TA = +25°C Vcc = 5V TA = +25°C, -15V ≤ VIN ≤ +15V
0.4 3.5 0.05 400 250 1.5 30 ±10
Volts Volts µA ns ns µs V/µs
IOUT = 3.2mA IOUT = 1.0mA EN = VCC, 0V≤VOUT ≤Vcc SP235A/B, SP236A/B, SP241A/B SP235A/B, SP236A/B, SP241A/B RS232 to TTL CL = 10pF, RL= 3–7kΩ; TA = +25°C CL = 2500pF, RL= 3kΩ; measured from +3V to -3V or -3V to +3V All transmitter outputs loaded with 3kΩ to Ground VCC= 0V; VOUT = ±2V Infinite duration
3 ±5 ±9
V/µs Volts Ohms mA
Output Resistance 300 RS-232 Output Short Circuit Current
±10
Date: 8/3/04
+ 5V Powered Multi-Channel RS-232 Drivers/Receivers
© Copyright 2004 Sipex Corporation
2
Transmitter Output Waveforms
TIN
5V 0V
TIN
5V 0V
0V TOUT
0V TOUT
No load
RL = 3kΩ, CL = 2,500pF
Transmitter Propagation Delay
TIN
TIN
TOUT
TOUT
Rise Time RL = 3kΩ; CL = 2,500pF All inputs = 20kHz
Fall Time RL = 3kΩ; CL = 2,500pF
Receiver Output Waveform
Shutdown to V+, V– Rise Time
SD In
5V 0V V+
0V Out V–
Date: 8/3/04
+ 5V Powered Multi-Channel RS-232 Drivers/Receivers
© Copyright 2004 Sipex Corporation
3
Receiver Propagation Delay
RIN
RIN
5V 0V
ROUT
5V 0V
ROUT
5V 0V
Fall Time
Rise Time
PINOUT
T3 OUT T1 OUT T2 OUT T2 IN T1 IN GND VCC C1 + V+ C1 -
1 2 3 4 5 6 7 8 9 10
20 19 18 17 16 15 14 13 12 11
T4 OUT T5 IN NC SD T5 OUT T 4 IN T 3 IN VC2 C2 +
T 1 OUT T2 OUT T2 IN T1 IN GND VCC C1+ V+
1 2 3
16 15 14
T3 OUT T 4 OUT T 4 IN T3 IN VC2 C2 + C1 -
T4 OUT T3 OUT T1 OUT T2 OUT R2 IN R 2 OUT T2 IN T1 IN R 1 OUT R 1 IN GND VCC
1 2 3 4 5
24 23 22 21 20
R3 IN R3 OUT T5 IN SD EN T5 OUT R4 IN R4 OUT T4 IN T3 IN R 5OUT R 5IN
SP234A
4 5 6 7 8
13 12 11 10 9
SP230A
1 2 3 4 5
SP235A
6 7 8 9 10 11 12
19 18 17 16 15 14 13
T4 OUT T3 OUT T1 OUT T2 OUT R2 IN R 2 OUT T2 IN T1 IN R 1 OUT R 1 IN GND VCC
24 23 22 21 20
R3 IN R3 OUT T5 IN SD EN T5 OUT R4 IN R4 OUT T4 IN T3 IN R 5OUT R 5IN
T3 OUT T1 OUT T2 OUT R1 IN R1 OUT T 2IN T1 IN GND VCC C1+ V+ C1-
1 2 3 4 5
24 23 22 21 20
T4 OUT R2 IN R2 OUT SD EN T4 IN T3 IN R 3 OUT R 3 IN VC2 C2 +
T3 OUT T1 OUT T2 OUT R1 IN R1 OUT T 2IN T1 IN GND VCC C1+ V+ C1-
1 2 3 4 5
24 23 22 21 20
T4 OUT R2 IN R2 OUT SD EN T4 IN T3 IN R 3 OUT R 3 IN VC2 C2 +
SP236B
SP235B
SP236A
6 7 8 9 10 11 12
19 18 17 16 15 14 13
6 7 8 9 10 11 12
19 18 17 16 15 14 13
6 7 8 9 10 11 12
19 18 17 16 15 14 13
Date: 8/3/04
+ 5V Powered Multi-Channel RS-232 Drivers/Receivers
© Copyright 2004 Sipex Corporation
4
Receiver Output Enable/Disable Times
5V EN IN 0V 5V EN IN 0V
5V ROUT 0V Disable
5V ROUT 0V Enable
PINOUT
T3 OUT T1 OUT T2 OUT R1 IN R1 OUT T2 IN T1 IN GND VCC C1+ V+ C1-
1 2 3 4 5
24 23 22 21 20
T4 OUT R2 IN R2 OUT T5 IN T5 OUT T4 IN T3 IN R 3OUT R 3IN VC2 C2 +
T2 OUT T1 OUT R 2IN R 2OUT T 1IN R 1 OUT R 1IN GND VCC C1+ V+ C1-
1 2 3 4 5
24 23 22 21 20
T3 OUT R3 IN R3 OUT T4 IN T4 OUT T3 IN T2 IN R 4OUT R 4IN VC2 C2 +
SP237A
SP238A
6 7 8 9 10 11 12
19 18 17 16 15 14 13
6 7 8 9 10 11 12
19 18 17 16 15 14 13
N.C. SHUTDOWN EN T5OUT R4IN R4OUT T4IN T3IN R5OUT R5IN N.C.
T 3OUT T 1OUT T2 OUT R 2 IN
33 32 31 30 29 28 27 26 25 24 23
N.C. N.C. N.C. V– C2– C2+ C1– V+ C1+ N.C. N.C.
1 2 3 4 5 6
28 27 26 25 24 23
T4 OUT R 3 IN R 3 OUT SHUTDOWN (SD) EN R 4 IN R 4 OUT T4 IN T3 IN R 5 OUT R 5 IN VC 2C 2+
T 3OUT T 1 OUT T2 OUT R 2 IN R 2 OUT T2 IN T1 IN R 1 OUT R 1 IN GND VCC C1 + V+ C1 -
1 2 3 4 5 6
28 27 26 25 24 23
T4 OUT R 3 IN R 3 OUT SHUTDOWN (SD) EN R 4 IN R 4 OUT T4 IN T3 IN R 5 OUT R 5 IN VC 2C 2+
44 43 42 41 40 39 38 37 36 35 34
N.C. T5IN R3OUT R3IN T4OUT T3OUT T1OUT T2OUT N.C. R2IN N.C.
1 2 3 4 5 6 7 8 9 10 11
R 2 OUT T2 IN T1 IN R 1 OUT R 1 IN GND VCC C1 + V+ C1 -
SP241A
SP241B
7 8 9 10 11 12 13 14
22 21 20 19 18 17 16 15
7 8 9 10 11 12 13 14
22 21 20 19 18 17 16 15
SP240A/B
Date: 8/3/04
N.C. R2OUT T2IN T1IN R1OUT R1IN GND VCC N.C. N.C. N.C.
12 13 14 15 16 17 18 19 20 21 22
+ 5V Powered Multi-Channel RS-232 Drivers/Receivers
© Copyright 2004 Sipex Corporation
5
FEATURES… The multi–channel RS-232 line drivers/receivers provides a variety of configurations to fit most communication needs, especially those applications where ±12V is not available. The SP230A, SP235A/B, SP236A/B, SP240A/B, and SP241A/B feature a shutdown mode which reduces device power dissipation to less than 5µW. All feature low power CMOS operation, which is particularly beneficial in batterypowered systems. The SP235A/B use no external components and are ideally suited where printed circuit board space is limited. All products in the Series include two charge pump voltage converters which allow them to operate from a single +5V supply. These converters convert the +5V input power to the ±10V needed to generate the RS-232 output levels. An internal charge pump converter produces the necessary –12V supply. All drivers and receivers meet all EIA RS-232D and CCITT V.28 specifications. The Series are available for use over the commercial, industrial and military temperature ranges. They are packaged in plastic DIP and SOIC packages. For product processed and screened to MIL–M–38510 and MIL–STD–883C requirements, please consult the factory.
THEORY OF OPERATION The SP230A/B–241A/B series devices are made up of three basic circuit blocks – 1) transmitter, 2) receiver and 3) charge pump. Each model within the series incorporates variations of these circuits to achieve the desired configuration and performance. Driver/Transmitter The drivers are inverting transmitters, which accept 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. Even under worst-case loading conditions of 3kΩ and 2500pF, the output is guaranteed to be ±5V, which is consistent with the RS-232 standard specifications. The transmitter outputs are protected against infinite short-circuits to ground without degradation in reliability. The drivers of the SP230A, SP235A/B, SP236A/B, SP240A/B and SP241A/B can be tri-stated by using the SHUTDOWN function. In this “power-off” state, the output impedance will remain greater than 300 Ohms, again satisfying the RS-232 specifications. Should the input of the driver be left open, an internal 400kΩ pull–up 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
20kbps
100kbps
10Mbps
10Mbps
64kbps
Table 1. EIA Standards Definition
Date: 8/3/04
+ 5V Powered Multi-Channel RS-232 Drivers/Receivers
© Copyright 2004 Sipex Corporation
6
standards [EIA RS-232–D 2.1.7, Paragraph (5)]. The transition of the loaded output from VOL to VOH clearly meets the monotonicity requirements of the standard [EIA RS-232–D 2.1.7, Paragraphs (1) & (2)]. Receivers The receivers convert RS-232 input signals to inverted TTL signals. Since the input is usually from a transmission line, where long cable lengths and system interference can degrade the signal, the inputs have a typical hysteresis margin of 500mV. This ensures that the receiver is virtually immune to noisy transmission lines. The input thresholds are 0.8V minimum and 2.4V maximum, again well within the ±3V RS-232 requirements. The receiver inputs are also protected against voltages up to ±30V. Should an input be left unconnected, a 5kΩ pulldown resistor to ground will commit the output of the receiver to a high state. In actual system applications, it is quite possible for signals to be applied to the receiver inputs before power is applied to the receiver circuitry. This occurs, for example, when a PC user attempts to print, only to realize the printer wasn’t turned on. In this case an RS-232 signal from the PC will appear on the receiver input at the printer. When the printer power is turned on, the receiver will operate normally. All series devices are fully protected. Again, to facilitate use in “real-world” applications, the receiver outputs can be tri–stated by bringing the ENABLE (EN) pin high, with the driver remaining full active. Charge Pump The charge pump section of the SP230A series allows the circuit to operate from a single +5V, ±10% power
10.5 10.0 9.5 9.0 8.5
V+ (Abs.)
S1
S3 V+ = 2VCC + + S4
V
CC
S2
C1
C3
GND
V
CC
INTERNAL OSCILLATOR
Figure 1. Charge Pump Voltage Doubler
supply by generating the required operating voltages internal to the devices. The charge pump consists of two sections — 1) a voltage doubler and 2) a voltage inverter. As shown in Figure 1, an internal oscillator triggers the charge accumulation and voltage inversion. The voltage doubler momentarily stores a charge on capacitor C1 equal to VCC, reference to ground. During the next transition of the oscillator this charge is boot–strapped to transfer charge to capacitor C3. The voltage across C3 is now from VCC to V+. In the inverter section (Figure 2), the voltage across C3 is transferred to C2 forcing a range of 0V to V+ across C2. Boot–strapping of C2 will then transfer charge to C4 to generate V-. The values of the capacitors are somewhat non-critical and can be varied, however the performance will be affected. As C3 and C4 are reduced, higher levels of ripple will appear. Lower values of C1 and C2 will increase the
10.5 10.0 9.5 9.0 8.5
V- (Abs.)
8.0 7.5 7.0 6.5 6.0 5.5 5.0 0 5 10 15 20 25
V =5.5V CC
8.0 7.5 7.0 6.5 V =5V CC VCC=4.5V V =5.5V CC
V =5V CC VCC=4.5V
6.0 5.5 5.0
30
35
40
0
5
10
15
20
25
30
35
40
a)
V+ IOUT (mA)
b)
V- I OUT (mA)
Charge Pump Output Loading versus VCC; a) V+; b) V–
Date: 8/3/04
+ 5V Powered Multi-Channel RS-232 Drivers/Receivers
© Copyright 2004 Sipex Corporation
7
SD 0 0 1 1
EN 0 1 0 1
Power Up/Down Up Up Down Down
Receiver Outputs Enable Tri–state Enable Tri–state
Table 2. Wake–Up Truth Table
ENABLE Input (EN) The SP235A/B, SP236A/B, SP240A/B, and SP241A/B all feature an enable input (EN), which allows the receiver outputs to be either tri–stated or enabled. The enable input is active low; 0V applied to EN will enable the receiver outputs. This can be especially useful when the receiver is tied directly to a microprocessor data bus. Protection From Shorts to >± 15V The driver outputs are protected against shorts to ground, other driver outputs, and V+ or V-. For protection against voltages exceeding ±15V, two back–to–back zener diodes connected to clamp the outputs to an acceptable voltage level are recommended. (Refer to Figure 3.) Improved Drive Capability for Mouse Applications Each of the devices in this data sheet have improved drive capability for non-standard applications. Although the EIA RS-232D standards specify the maximum loading to be 3kΩ and 2500pF, the SP230A, SP234A, SP235A/B, SP236A/B, SP237A, SP238A, SP240A/B, and SP241A/B can typically drive loads as low as 1kΩ and still maintain ±5V outputs. This feature is especially useful when the serial port is intended to be used for a “self-powered” mouse. In this case the voltage necessary to operate the circuits in the mouse can be derived from the RS-232 driver output as long as the loading is ≥1kΩ (refer to Figure 4). For applications which even exceed this requirement, drivers can be connected in parallel, increasing the drive capability to 750Ω, while maintaining the ±5V VOH and VOL levels (refer to Figure 5).
output impedance of V+ and V-, which will degrade VOH and VOL. Capacitor values can be as low as 1.0µF. Shutdown (SD) TheSP230A, SP235A/B, SP236A/B, SP240A/ B and SP241A/B all feature a control input which will disable the part and reduce VCC current typically to less than 5µA, which is especially useful to designers of battery–powered systems. In the “power–off” mode the receiver and transmitter will both be tri-stated. V+ will discharge to VCC, and V- will discharge to ground. For complete shutdown to occur and the 10µA current drain to be realized, the following conditions must be met:
• +5.00V must be applied to the SD pin; • ENABLE must either 0V, +5.0V or not connected; • the transmitter inputs must be either +5.0V or not connected; • VCC must be +5V; • Receiver inputs must be >0V and