MAXIM MAX214CWI

19-0199; Rev 1; 8/95
Programmable DTE/DCE,
+5V RS-232 Transceiver
____________________________Features
♦ Eliminates Null Modem Cables
________________________Applications
♦ Receivers Active in Shutdown
AT-Compatible Laptop Computers
♦ Programmable DTE or DCE Serial Port
♦ 1µF Charge-Pump Capacitors
♦ 116kbps Data Rate—Guaranteed
♦ 20µA Shutdown Mode
______________Ordering Information
AT-Compatible Desktop Computers
PART
Modems, Printers, and Other Peripherals
__________Typical Operating Circuit
+5V
TEMP. RANGE
PIN-PACKAGE
MAX214CPI
0°C to +70°C
28 Plastic DIP
MAX214CWI
0°C to +70°C
28 Wide SO
MAX214C/D
0°C to +70°C
Dice*
MAX214EPI
-40°C to +85°C
28 Plastic DIP
MAX214EWI
-40°C to +85°C
28 Wide SO
* Dice are specified at TA = +25°C.
1µF
16
27
1µF
1µF
1µF
VCC
C1+
15
__________________Pin Configuration
V+
28
C11
C2+
2
MAX214
V-
14
C2-
5 TA
DTE
TRA 9
DCE
6 RA
RTA 10
DTE
25 TB
TRB 20
DTE
DCE
23 RB
RTB 19
DTE
24
TC
TRC 18
DTE
DCE
22 RC
RTC 17
DTE
DCE
DCE
7 RDC
21
26
3
RRE 12
RE
DTE/DCE
SHDN
HI-Z
RDTC 11
DTE
DTE
8
TOP VIEW
1µF
C2+
1
28
C1-
C2-
2
27
C1+
HI-Z
3
26
SHDN
N.C.
4
25
TB
TA
5
24
TC
RA
6
23
RB
RDC
7
22
RC
RE
8
21
DTE/DCE
TRA
9
20
TRB
RTA 10
19
RTB
RDTC 11
18
TRC
RRE 12
17
RTC
GND 13
16
VCC
V- 14
15
V+
MAX214
GND
13
DIP/SO
________________________________________________________________ Maxim Integrated Products
Call toll free 1-800-998-8800 for free samples or literature.
1
MAX214
_______________General Description
The MAX214 +5V RS-232 transceiver provides a complete, 8-line, software-configurable, DTE or DCE port
RS-232 interface. Tx, Rx, RTS, CTS, DTR, DSR, DCD,
and RI circuits can be configured as either Data
Terminal Equipment (DTE) or Data Circuit-Terminating
Equipment (DCE) using the DTE/DCE control pin. The
MAX214 eliminates the need to swap cables when
switching between DTE and DCE configurations.
MAX214
Programmable DTE/DCE,
+5V RS-232 Transceiver
ABSOLUTE MAXIMUM RATINGS
VCC ...........................................................................-0.3V to +6V
Input Voltages
TIN, DTE/DCE, SHDN HI-Z ......................-0.3V to (VCC + 0.3V)
RIN ....................................................................................±15V
Output Voltages:
TOUT ..................................................................................±15V
ROUT ........................................................-0.3V to (VCC + 0.3V)
Short-Circuit (one output at a time)
TOUT to GND ...........................................................Continuous
ROUT to GND...........................................................Continuous
Continuous Power Dissipation (TA = +70°C)
Plastic DIP (derate 9.09mW/°C above +70°C) .............727mW
Wide SO (derate 12.50mW/°C above +70°C) ............1000mW
Operating Temperature Ranges:
MAX214C–I ..............................................0°C to +70°C
MAX214E –I ..........................................-40°C to +85°C
Storage Temperature Range ......................-65°C to +150°C
Lead Temperature (soldering, 10sec) .......................+300°C
Stresses beyond 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 beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(VCC = 4.5V to 5.5V, C1 to C4 = 1µF, TA = TMIN to TMAX, unless otherwise noted.)
PARAMETER
CONDITIONS
MIN
TYP
0.8
1.4
MAX
UNITS
RS-232 TRANSMITTERS
Logic Input Threshold Low
Logic Input Threshold High
Logic Input Pull-Up Current
Normal operation
1
Shutdown
V
1.4
2.0
10
50
±0.01
±1
V
µA
Output Voltage Swing
All transmitter outputs loaded with 3kΩ to ground
±5.0
±7.5
V
Transmitter Output Resistance
VCC = V+ = V- = 0V, VOUT = ±2V (Note 1)
300
300k
Ω
Output Short-Circuit Current
VOUT = 0V
±7
±25
mA
Positive Threshold Input Low
TA = +25°C, VCC = 5V, normal operation, SHDN = 0V
0.8
1.3
Positive Threshold Input High
TA = +25°C, VCC = 5V, normal operation, SHDN = 0V
Positive Threshold Input
Hysteresis
VCC = 5V, normal operation, SHDN = 0V (no hysteresis
in shutdown)
Negative Threshold Input Low
TA = +25°C, VCC = 5V
Negative Threshold Input High
TA = +25°C, VCC = 5V
Negative Threshold Input
Hysteresis
VCC = 5V, normal operation, SHDN = 0V (no hysteresis
in shutdown)
HI-Z = 0V and SHDN = 0V
HI-Z = 5V or SHDN = 5V
RS-232 RECEIVERS
Input Voltage Operating Range
Input Resistance
±15
TTL/CMOS Output Voltage Low
IOUT = 3.2mA
TTL/CMOS Output Voltage High
IOUT = -1.0mA
2
V
V
1.8
2.4
V
0.2
0.5
1.0
V
Normal operation, SHDN = 0V
-2.6
-1.9
Shutdown, SHDN = 5V
0.8
1.3
V
Normal operation, SHDN = 0V
-1.5
-0.2
Shutdown, SHDN = 5V
1.3
2.4
0.2
0.4
1.0
3
100
5
300
7
0.2
0.4
3.5
VCC - 0.2
_______________________________________________________________________________________
V
V
kΩ
V
V
Programmable DTE/DCE,
+5V RS-232 Transceiver
(VCC = 4.5V to 5.5V, C1 to C4 = 1µF, TA = TMIN to TMAX, unless otherwise noted.)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
POWER SUPPLY
VCC Supply Current
Shutdown Supply Current
No load, TA = +25°C
DTE/DCE = 0V, SHDN =
HI-Z = VCC , Figure 1
TA = +25°C
9
20
mA
4
20
µA
50
TA = TMIN to TMAX
CONTROL LOGIC (DTE/DCE, SHDN, HI-Z)
Logic Input Threshold Low
0.8
Logic Input Threshold High
1.3
1.3
Input Leakage Current
V
2.0
V
±1
µA
AC CHARACTERISTICS
Data Rate
Normal operation, transmitters and receivers
200
Receivers in shutdown mode
20
TA = +25°C, VCC = 5V, RL = 3kΩ to 7kΩ,
CL = to 2500pF,
measured from 3V to -3V or -3V to 3V
116
kbps
12
30
V/µs
tPHLT
1.3
3.5
tPLHT
1.4
3.5
µs
Transmitter + to - Propagation-Delay
Difference (Normal Operation)
tPHLT - tPLHT
100
Receiver Propagation Delay,
RS-232 to TTL (Normal Operation)
tPHLR, t PLHR
0.4
1.5
µs
tPHLR
0.4
10
tPLHR
1.5
10
µs
Transition-Region Slew Rate
Transmitter Propagation Delay,
TTL to RS-232 (Normal Operation)
Receiver Propagation Delay,
RS-232 to TTL (Shutdown Mode)
Receiver Propagation-Delay Difference
tPHLT - tPLHT
(Normal Operation)
6
ns
100
ns
MODE-CHANGE TIMING (DTE/DCE)
Transmitter Enable Time
tTEN (includes charge-pump start-up time)
250
µs
Transmitter Disable Time
tTTR
600
ns
Transmitter DTE/DCE Switch Time
tTSW
600
ns
Receiver DTE/DCE Switch Time
tRSW
300
ns
Receiver Termination-Resistor
Connect/Disconnect Time
(SHDN = 0V)
300
ns
Receiver Termination-Resistor Connect
Entering SHDN Time
250
µs
Receiver Termination-Resistor
Disconnect Exiting SHDN Time
300
ns
Note 1: The 300Ω minimum is the EIA/TIA-232E specification, but the actual resistance when in shutdown mode or when VCC = 0V
is typically 300kΩ.
_______________________________________________________________________________________
3
MAX214
ELECTRICAL CHARACTERISTICS (continued)
__________________________________________Typical Operating Characteristics
(VCC = 5V, C1 to C4 = 1µF, all transmitters loaded with 3kΩ in parallel with 2.5nF, TA = +25°C, unless otherwise noted.)
TRANSMITTER OUTPUT VOLTAGE (VOH)
vs. LOAD CAPACITANCE
AT DIFFERENT DATA RATES
-6.0
20kbps
7.4
120kbps
7.2
64kbps
V OH (V)
-7.0
V OH (V)
6.8
120kbps
6.6
8.0
7.5
6.4
20kbps
7.0
6.2
DATA RATE = 0kbps
6.0
-8.5
0
6.5
0
1000 2000 3000 4000 5000 6000 7000
LOAD CAPACITANCE (pF)
1 TRANSMITTER LOADED
-8.0
-8.5
DATA RATE = 0kbps
-9.5
16
4
V+ AND VEQUALLY
0 LOADED
2
V- LOADED,
NO LOAD
ON V+
V+ LOADED,
NO LOAD
ON V-
-2
ALL TRANSMITTERS UNLOADED, 0kbps
-4
14
SLEW+
1 TRANSMITTER LOADED
12
10
8
SLEW6 1 TRANSMITTER LOADED
-8
4
-10
4.5 4.6 4.7 4.8 4.9 5.0 5.1 5.2 5.3 5.4 5.5
V CC (V)
SLEW+
3 TRANSMITTERS LOADED
SLEW3 TRANSMITTERS LOADED
18
6
-6
-9.0
20
MAX214-05
8
T OUT +, T OUT - (V)
2 TRANSMITTERS LOADED
SLEW RATE vs. LOAD CAPACITANCE
10
MAX214-04
3 TRANSMITTERS LOADED
4.5 4.6 4.7 4.8 4.9 5.0 5.1 5.2 5.3 5.4 5.5
V CC (V)
TRANSMITTER OUTPUT VOLTAGES
vs. V+, V- LOAD CURRENT
TRANSMITTER OUTPUT VOLTAGE (VOL)
vs. POSITIVE SUPPLY VOLTAGE
-7.0
1000 2000 3000 4000 5000 6000 7000
LOAD CAPACITANCE (pF)
0
20
40
60
LOAD CURRENT (mA)
80
0
2000
4000
6000
LOAD CAPACITANCE (pF)
_______________________________________________________________________________________
MAX214-06
-8.0
SLEW RATE (V/µs)
V OL (V)
3 TRANSMITTERS LOADED
64kbps
7.0
-7.5
4
1 TRANSMITTER LOADED
2 TRANSMITTERS LOADED
8.5
-6.5
-7.5
9.0
MAX214-02
7.6
MAX214-01
-5.5
TRANSMITTER OUTPUT VOLTAGE (VOH )
vs. VCC POSITIVE SUPPLY VOLTAGE
MAX214-03
TRANSMITTER OUTPUT VOLTAGE (VOL)
vs. LOAD CAPACITANCE
AT DIFFERENT DATA RATES
V OL (V)
MAX214
Programmable DTE/DCE,
+5V RS-232 Transceiver
Programmable DTE/DCE,
+5V RS-232 Transceiver
PIN
NAME
FUNCTION
1, 2
C2+, C2-
3
HI-Z
RS-232 receiver impedance control. Take high to disconnect the termination resistor.
4
N.C.
No connect—not internally connected
Terminals for negative charge-pump capacitor
5, 24, 25
TA, TC, TB
6, 8, 22, 23
RA, RE, RC, RB
7
RDC
9, 18, 20
TRA, TRC, TRB
RS-232 DTE driver output for DTE/DCE= 0V, or RS-232 DCE receiver input for DTE/DCE = +5V
10, 17, 19
RTA, RTC, RTB
RS-232 DTE receiver input for DTE/DCE = 0V, or RS-232 DCE driver output for DTE/DCE = +5V
11
RDTC
12
RRE
RS-232 receiver input
13
GND
Ground
14
V-
-2VCC voltage generated by the charge pump
15
V+
+2VCC voltage generated by the charge pump
16
VCC
+4.5V to +5.5V supply voltage
21
DTE/DCE
26
SHDN
27, 28
C1+, C1-
TTL/CMOS driver A, C, B inputs
TTL/CMOS receiver A, E, C, B outputs
TTL/CMOS DTE receiver output D for DTE/DCE = 0V, or TTL/CMOS DCE receiver output C for
DTE/DCE = +5V
RS-232 DTE receiver input D for DTE/DCE = 0V, or RS-232 DCE driver output C for
DTE/DCE = +5V
Data terminal equipment (DTE) and data circuit-terminating equipment (DCE) control pin.
DCE active high and DTE active low.
Shutdown control; shutdown high, normal operation low
Terminals for positive charge-pump capacitor
_______________Detailed Description
The MAX214 RS-232 transceiver provides a complete,
8-line, software-configurable, DTE or DCE port RS-232
interface. Tx, Rx, RTS, CTS, DTR, DSR, DCD, and RI
circuits can be configured as either Data Terminal
Equipment (DTE) or Data Circuit-Terminating
Equipment (DCE) using the DTE/DCE control pin. The
MAX214 eliminates the need to swap cables when
switching between DTE and DCE configurations. This
is useful when, for example, a portable computer is
required to communicate with printers, modems, and
other computers without carrying multiple cables.
The MAX214 runs from a single +5V supply and incorporates a dual charge-pump voltage converter to generate the necessary voltages for the RS-232 transmitters.
A shutdown mode is provided to save power when
transmission is not required, but the receivers always
stay active for simple detection of ring indicator signals.
DTE/DCE Operation
The DTE/DCE pin allows circuit configuration under
software control. Tables 1a and 1b show the pin definitions of the MAX214 in both DTE and DCE modes. The
Function columns show the direction of data flow from
the input pin to the output pin of the MAX214, and onto
the corresponding DB-25 connector’s pin.
+5V to ±10V Dual Charge-Pump
Voltage Converter
The +5V to ±10V conversion is performed by two
charge-pump voltage converters (Figure 2). The first
uses capacitor C1 to double the +5V to +10V, storing
the +10V on the output filter capacitor, C3. The second
charge-pump voltage converter uses C2 to invert the
+10V to -10V, storing the -10V on the V- output filter
capacitor, C4.
In shutdown mode, V+ is pulled to VCC by an internal
resistor, and V- falls to GND.
_______________________________________________________________________________________
5
MAX214
______________________________________________________________Pin Description
Table 1a. DTE-Operation Pin Configurations
TTL/CMOS
I/O LABEL
MAX214
PIN
FUNCTION
MAX214
PIN
RS-232
I/O LABEL
DB-25
PIN
INPUT
THRESHOLD
Transmitter (TxD)
5
9
TxD
2
Receiver (RxD)
6
10
RxD
3
Request to Send (RTS)
25
20
RTS
4
Clear to Send (CTS)
23
19
CTS
5
Data Terminal Ready (DTR)
24
18
DTR
20
Data Set Ready (DSR)
22
17
DSR
6
-
Detector Carrier Data (DCD)
7
11
DCD
8
+
Ring Indicator (RI)
8
12
RI
22
+
-
+
Table 1b. DCE-Operation Pin Configurations
MAX214
PIN
MAX214
PIN
RS-232
I/O LABEL
DB-25
PIN
5
10
RxD
3
6
9
TxD
2
25
19
CTS
5
23
20
RTS
4
17
DSR
6
11
DCD
8
18
DTR
20
-
12
RI
22
+
FUNCTION
INPUT
THRESHOLD
+
-
24
22
7
8
6
_______________________________________________________________________________________
MAX214
MAX214
Programmable DTE/DCE,
+5V RS-232 Transceiver
Programmable DTE/DCE,
+5V RS-232 Transceiver
ISHDN
+5.5V
1µF
1µF
VCC
C1+
1µF
V+
1µF
C1-
MAX214
V-
C2+ +5V
1µF
C2-
400k
Tx
TIN
+5.5V
3k
Rx
ROUT
0V OR +5.5V
DRIVE
TOUT
RIN
5k
DTE/DCE
+5.5V
HI-Z
+5.5V
SHDN
+5.5V
GND
RS-232 Receivers
CAPACITORS MAY BE
POLARIZED OR UNPOLARIZED
The receivers convert the RS-232 signals to
CMOS-logic levels. They invert, to match the inversion
of RS-232 drivers. The guaranteed receiver input
thresholds are significantly tighter than the ±3V
thresholds required by the EIA/TIA-232E specification,
Figure 1. MAX214 Shutdown-Current Test Circuit
V+
S1
V CC
S2
C1+
C1
S3
S5
C3
S4
GND
GND
C2
RL +
C4
S7
V CC
C1-
IL +
C2+ S6
IL -
RL -
S8
VC2-
120kHz
Figure 2. Charge-Pump Diagram
_______________________________________________________________________________________
7
MAX214
RS-232 Drivers
With VCC = 5V, the typical driver output voltage swing
is ±8V when loaded with a nominal 5kΩ RS-232
receiver. Under worst-case operating conditions
(including 116kbps data rate, 3kΩ  2500pF load,
VCC = 4.5V, maximum rated temperature) the output
swing is guaranteed to meet the ±5V minimum specified by EIA/TIA-232 and V.28. The open-circuit output
voltage swing ranges from (V+ - 0.6V) to V-.
Input thresholds are both CMOS and TTL compatible.
The inputs of unused drivers can be left unconnected
because 400kΩ pull-up resistors to VCC are included
on-chip. Since all drivers invert, the pull-up resistors
force the outputs of unused drivers low. The input
pull-up resistors typically source 10µA; in shutdown
mode, they are disconnected to reduce supply current.
When in low-power shutdown mode, the driver outputs
are turned off and their leakage current is less than
1µA, even if the transmitter output is back-driven with
voltages up to ±15V.
MAX214
Programmable DTE/DCE,
+5V RS-232 Transceiver
Table 2. Control Pin Configurations
CONTROL INPUTS
RS-232 PINS
SHUTDOWN
HI-Z
DTE/DCE
TRA, TRB, TRC
0
0
0
Transmit Mode
Receive Mode/5kΩ
Receive Mode/5kΩ
0
0
1
Receive Mode/5kΩ
Transmit Mode
Receive Mode/5kΩ
0
1
0
Transmit Mode
Receive Mode/HI-Z
Receive Mode/HI-Z
0
1
1
Receive Mode/HI-Z
Transmit Mode
Receive Mode/HI-Z
1
0
0
Disabled/HI-Z
Slow Receive/HI-Z
Slow Receive/HI-Z
1
0
1
Slow Receive/HI-Z
Disabled/HI-Z
Slow Receive/HI-Z
1
1
0
Disabled/HI-Z
Slow Receive/HI-Z
Slow Receive/HI-Z
1
1
1
Slow Receive/HI-Z
Disabled/HI-Z
Slow Receive/HI-Z
which improves noise margins. The polarity of each
receiver’s input threshold is shown in Tables 1a and 1b.
In normal operating mode, receiver inputs are internally
connected to ground with 5kΩ resistors. So unconnected receivers with positive input thresholds have
high outputs, and those with negative input thresholds
have low outputs.
When shut down, all receivers have positive thresholds.
This allows the receiver inputs to respond to
TTL-/CMOS-logic levels, as well as RS-232 levels. The
guaranteed 0.8V input threshold ensures that receivers
shorted to ground will have a logic 1 output. Also, the
300kΩ input resistance to ground ensures that a receiver with its input left open will also have a logic 1 output.
The receiver’s 0.5V of hysteresis provides clean output
transitions, even with slow rise-time and fall-time signals with moderate amounts of noise and ringing. The
receivers have no hysteresis in shutdown mode.
HI-Z Control
The receiver inputs are terminated with 5kΩ resistors, to
comply with the requirements of EIA/TIA-232E.
However, these internal resistors can be disconnected
by taking the HI-Z control pin to a logic high. This
makes all of the MAX214’s receiver inputs high impedance, and facilitates the transmission of RS-232 data
from a single transmitter to multiple receivers. In this
case, all but one of the receiving ICs should be put into
the high input-impedance state.
8
RTA, RTB, RTC, RDTC
RRE
Shutdown Control
In shutdown mode, the charge pumps are turned off,
V+ is pulled down to VCC, V- is pulled to ground, and
the transmitter outputs are disabled. This reduces supply current typically to 4µA. The time required to exit
shutdown is about 250µs, as shown in Figure 3.
Receivers
Receiver outputs never go into a high-impedance state;
they are always active, even in shutdown mode (see
Table 2). These awake-in-shutdown receivers are useful for monitoring external activity (for example, on RI),
while maintaining minimal power consumption.
Receivers in shutdown mode are slower (20kbps) than
when not shut down (116kbps), and lack the hysteresis
present in normal operation.
Drivers
The driver outputs are high impedance in shutdown
mode, even when back-driven with voltages up
to ±15V.
__________Applications Information
Capacitor Selection
The type of capacitor (C1 to C4) used is not critical for
proper operation. The MAX214 requires 1µF capacitors, although in all cases capacitors of up to 10µF
can be used without harm. Ceramic dielectrics are
suggested for the 1µF capacitors.
_______________________________________________________________________________________
Programmable DTE/DCE,
+5V RS-232 Transceiver
pump capacitor sizes up to 10µF reduces the impedance of the V+ and V- outputs.
High Data Rates
The MAX214 maintains the RS-232 ±5.0V minimum
driver output voltage even at high data rates. The
Typical Operating Characteristics show transmitter output voltage levels driving 3kΩ in parallel with various
capacitive loads at data rates up to 120kbps.
To reduce the output impedance at V+ and V-, use
larger capacitors (up to 10µF). This can be useful
when “stealing” power from V+ or from V-.
+10V
A
+5V
Driver Outputs when Exiting Shutdown
Figure 3 shows the MAX214 driver outputs when exiting
shutdown. As they become active, the two driver outputs are shown going to opposite RS-232 levels (one
driver input is high, the other is low). Each driver is
loaded with 3kΩ in parallel with 2.5nF.
0V
-5V
B
-10V
+5V
C
0V
Power-Supply Bypassing
Decouple VCC to ground with a capacitor of the same
value as the charge-pump capacitors.
V+ and V- as Power Supplies
A small amount of power can be drawn from V+ and V-,
although this will reduce noise margins. See the
Output Voltage vs. Load Current graph in the Typical
Operating Characteristics. Increasing the charge-
A = TRANSMITTER OUTPUT HIGH, +5V/div
B = TRANSMITTER OUTPUT LOW, +5V/div
C = SHDN INPUT, +5V/div
HORIZONTAL = 200µs
Figure 3. Transmitter Outputs When Exiting Shutdown
_______________________________________________________________________________________
9
MAX214
When using the minimum recommended capacitor
values, make sure the capacitance value does not
degrade excessively as the operating temperature
varies. If in doubt, use capacitors with a
larger nominal value (for example, 2 times larger).
The effective series resistance (ESR) of the capacitors may vary over temperature and increase
when below 0°C. ESR influences the amount of ripple on V+ and V-, so if low ripple is required over
wide temperature ranges, use larger capacitors or
low-ESR types.
MAX214
Programmable DTE/DCE,
+5V RS-232 Transceiver
STANDARD
RS-232
CABLE
PC1
(DTE MODE)
PC2
(DCE MODE)
5
TA
TRA
9
3
TxD
3
9
TRA
TA 5
6
RA
RTA
10
2
RxD
2
10
RTA
RA 6
25
TB
TRB
20
7
RTS
7
20
TRB
TB 25
23
RB
RTB
19
8
CTS
8
19
RTB
RB 23
24
TC
TRC
18
4
DTR
4
18
TRC
TC 24
22
RC
RTC
17
6
DSR
6
17
RTC
RC 22
RDTC
11
1
DCD
1
11
RDTC
RRE
12
9
RI
9
12
RRE
7
RDC
8
RE
RDC 7
MAX214
MAX214
RE 8
HIGH
HIGH
HI-Z
SHDN
3
26
DTE/DCE
21
DB-9 CONNECTORS
HI-Z
SHDN
3
26
DTE/DCE
POWER CONNECTIONS OMITTED FOR CLARITY.
Figure 4. Typical Application Circuit Showing 2 PCs with Both DTE and DCE Operation
10
______________________________________________________________________________________
21
V CC
Programmable DTE/DCE,
+5V RS-232 Transceiver
EIA/TIA-232E, V.28
SPECIFICATIONS
PARAMETER
CONDITIONS
Driver Output
Voltage
0 Level
1 Level
Output Level, Max
3kΩ to 7kΩ load
+5.0V to +15V
3kΩ to 7kΩ load
-5.0V to -15V
No load
±25V
3kΩ ≤ RL ≤ 7kΩ,
CL ≤ 2500pF
Up to 20kbits/sec
Data Rate
Receiver Input
Voltage
0 Level
1 Level
Input Level, Max
Instantaneous
Slew Rate, Max
Driver Output
Resistance
HI-Z
C2- C1C2+
C1+
SHDN
TB
TA
TC
RA
RB
RDC
RC
+3.0V to +15V
0.178"
4.52mm
RE
-3.0V to -15V
DTE/DCE
±25V
3kΩ ≤ RL ≤ 7kΩ,
CL ≤ 2500pF
Driver Output
Short-Circuit
Current, Max
Transition Rate on
Driver Output
___________________Chip Topography
TRA
30V/µs
TRB
RTB
RTA
100mA
RRE
V.28
1ms or 3% of the
period
EIA/TIA-232E
4% of the period
GND
RDTC
TRC
V+
V-
VCC
RTC
0.156"
3.96mm
TRANSISTOR COUNT: 694;
SUBSTRATE CONNECTED TO V+.
-2V < VOUT < +2V 300Ω
Table 4. DB9/DB25 Cable Connections Commonly Used for EIA/TIA-232 and V.24
Asynchronous Interfaces
DB9 PIN
DB25 PIN
NAME
SYMBOL
1
8
Received Line Signal Detector, sometimes
called Data Carrier Detect
FUNCTION
DCD
Handshake from DCE
2
3
Receive Data
RxD
Data from DCE
3
2
Transmit Data
TxD
Data from DTE
4
20
Data Terminal Ready
DTR
Handshake from DTE
5
7
Signal Ground
GND
Reference point for signals
6
6
Data Set Ready
DSR
Handshake from DCE
7
4
Request to Send
RTS
Handshake from DTE
8
5
Clear to Send
CTS
Handshake from DCE
9
22
Ring Indicator
RI
Handshake from DCE
______________________________________________________________________________________
11
MAX214
Table 3. Summary of EIA/TIA-232E, V.28
Specifications
MAX214
Programmable DTE/DCE,
+5V RS-232 Transceiver
________________________________________________________Package Information
DIM
D1
A
A1
A2
A3
B
B1
C
D
D1
E
E1
e
eA
eB
L
α
E
A2
A3
E1
D
A
α
A1
e
C
L
eA
B1
eB
B
DIM
E
A
A1
B
C
D
E
e
H
h
L
α
H
INCHES
MAX
MIN
0.200
–
–
0.015
0.175
0.125
0.080
0.055
0.020
0.016
0.065
0.045
0.012
0.008
1.470
1.430
0.090
0.050
0.625
0.600
0.575
0.525
0.100 BSC
0.600 BSC
0.700
–
0.150
0.125
15˚
0˚
MILLIMETERS
MIN
MAX
–
5.08
0.38
–
3.18
4.45
1.40
2.03
0.41
0.51
1.14
1.65
0.20
0.30
36.32
37.34
1.27
2.29
15.24
15.88
13.34
14.61
2.54 BSC
15.24 BSC
–
17.78
3.18
3.81
0˚
15˚
21-342A
28-PIN PLASTIC
DUAL-IN-LINE
PACKAGE
INCHES
MAX
MIN
0.104
0.093
0.012
0.004
0.019
0.014
0.013
0.009
0.713
0.697
0.299
0.291
0.050 BSC
0.419
0.394
0.030
0.010
0.050
0.016
8˚
0˚
MILLIMETERS
MIN
MAX
2.35
2.65
0.10
0.30
0.35
0.49
0.23
0.32
17.70
18.10
7.40
7.60
1.27 BSC
10.00
10.65
0.25
0.75
0.40
1.27
0˚
8˚
21-343A
D
h x 45˚
α
A
0.127mm
0.004in.
e
B
A1
C
L
28-PIN PLASTIC
SMALL-OUTLINE
PACKAGE
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
12 __________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600
© 1995 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.