MAXIM MAX212 User Manual
19-0162; Rev 2; 2/94
EVALUATION KIT
INFORMATION INCLUDED
+3V-Powered, Low-Power,
True RS-232 Transceiver
________________General Description
The MAX212 RS-232 transceiver is intended for 3V-powered EIA/TIA-232E and V.28/V.24 communication interfaces where 3 drivers and 5 receivers are needed with
minimum power consumption. The operating voltage
range extends from 3.6V down to 3.0V while still maintaining true RS-232 and EIA/TIA-562 voltage levels.
A 1µA typical shutdown mode reduces power consumption, extending battery life in portable systems.
While shut down, all receivers can remain active or can
be disabled under logic control. This enables a system
incorporating the CMOS MAX212 to be in low-power
shutdown mode and monitor incoming RS-232 activity.
A guaranteed data rate of 120kbps provides compatibility with popular software for communicating with personal computers.
Three-state drivers on all receiver outputs are provided
so that multiple receivers, generally of different interface standards, can be wire-ORed at the UART.
The MAX212 is available in both small-outline (SO) and
shrink-small-outline (SSOP) packages. The SSOP
package occupies less than half of the board area
required by the equivalent SO package.
________________________Applications
Computers
Notebooks/Palmtops/Subnotebooks
Printers
Peripherals
Instruments
_______________Ordering Information
PART TEMP. RANGE PIN-PACKAGE
MAX212CWG 0°C to +70°C 24 Wide SO
MAX212CAG 0°C to +70°C 24 SSOP
MAX212C/D 0°C to +70°C Dice*
MAX212EWG -40°C to +85°C 24 Wide SO
MAX212EAG -40°C to +85°C 24 SSOP
* Dice are tested at TA= +25°C only.
____________________________Features
SUPERIOR TO BIPOLAR:
♦ Operates from Single +3.0V to +3.6V Supply
♦ 24-Pin SSOP or Wide SO Packages
♦ Meets All EIA/TIA-232E & EIA/TIA-562
Specifications
♦ 3mA Max Supply Current (Unloaded)
♦ 1µA Low-Power Shutdown Mode
♦ All Receivers Active During Low-Power Shutdown
♦ Mouse Compatible at 3.0V
♦ Low-Cost, Surface-Mount External Components
♦ 120kbps Guaranteed Data Rate—LapLink™
Compatible
♦ Three-State Receiver Outputs
♦ Evaluation Kit Available
♦ Flow-Through Pinout
___________T ypical Operating Circuit
+3.3V
SHUTDOWN
1
LN
3
V
CC
DC-DC CONVERTER
4
SD
T1
11
IN
T2
12 16
IN
T3
13 15
IN
R1
622
OUT
R2
721
OUT
R3
820
OUT
MAX212
T1
T2
T3
21423
LP V-V+
T1
17
OUT
T2
OUT
T3
OUT
R1
IN
R1
R2
IN
R2
R3
IN
R3
MAX212
EV KIT TEMP. RANGE BOARD TYPE
R4
919
OUT
MAX212EVKIT-SSOP 0°C to +70°C Surface Mount
R5
10 18
OUT
EN
5
™LapLink is a registered trademark of Traveling Software.
ENABLE
________________________________________________________________
Call toll free 1-800-998-8800 for free samples or literature.
R4
IN
R4
R5
IN
R5
GND
24
Maxim Integrated Products
1
+3V-Powered, Low-Power,
True RS-232 Transceiver
ABSOLUTE MAXIMUM RATINGS
Supply Voltages
.....................................................................-0.3V to +4.6V
V
CC
V+............................................................(V
V-........................................................................-7.4V to +2.0V
LN..............................................................-0.3V to (V+ + 1.0V)
LP.......................................................(V- - 1.0V) to (V+ + 0.3V)
Input Voltages
MAX212
, –S—D, EN..............................................-0.3V to (V+ + 0.3V)
T_
IN
...................................................................................±25V
R_
IN
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.
- 0.3V) to +7.4V
CC
Output Voltages
T_
................................................................................±15V
OUT
........................................................-0.3V to (V+ + 0.3V)
R_
OUT
Short-Circuit Duration, T_
Continuous Power Dissipation (T
Wide SO (derate 11.76mW/°C above +70°C)...............941mW
SSOP (derate 8.00mW/°C above +70°C) .....................640mW
Lead Temperature (soldering, 10sec).............................+300°C
.....................................Continuous
OUT
= +70°C)
A
ELECTRICAL CHARACTERISTICS
(VCC= 3.0V to 3.6V, TA= T
PARAMETER MIN TYP MAX UNITS
DC CHARACTERISTICS
Operating Voltage Range 3.0 3.6 V
VCCSupply Current 1.5 3.0 mA
Shutdown Supply Current 115µA
Shutdown Supply Current with
Receivers Active
LOGIC
Input Logic Threshold Low V
Input Logic Threshold High 2V
Input Current High 1 µA
Input Current Low 1 µA
Hysteresis 0.3 V
Logic Output Voltage Low 0.25 V
Logic Output Voltage High V
Logic Output Leakage Current ±10 µA
EIA/TIA-232E RECEIVERS
EIA/TIA-232E Input Voltage
Operating Range
EIA/TIA-232E Input Voltage
Threshold Low
EIA/TIA-232E Input Voltage
Threshold High
EIA/TIA-232E Input Hysteresis 0.7 V
EIA/TIA-232E Input Resistance 357kΩ
EIA/TIA-232E TRANSMITTERS
Output Voltage Swing (V
Output Resistance 300 Ω
EIA/TIA-232E Short-Circuit Current
MIN
HIGH
to T
, unless otherwise noted.)
MAX
Meets or exceeds EIA/TIA-232E specifications
No load, VCC= 3.3V
–S—
D= EN = GND, R_
–S—
D = GND, EN = V
T_IN, EN, –S—D; VCC= 3.0V to 3.6V
T_IN, EN, –S—D; VCC= 3.0V to 3.6V
T_IN, EN, –S—D; VIN= V
T_IN, EN, –S—D, VIN= GND
T_IN; V
I
OUT
I
OUT
EN = GND, 0V < R_
-15V < VIN< 15V
, V
All transmitters loaded 3kΩ to GND
)
LOW
VCC= V- = V+ = 0V, -2V < T_
= 3.3V
CC
= 1.0mA
= -1.0mA
CONDITIONS
= GND or V
IN
, R_IN= GND or V
CC
CC
< V
OUT
CC
OUT
CC
< 2V
CC
115µA
/ 3 V
CC
/ 3 V
CC
- 0.5 V
CC
-25 +25 V
0.4 V
2.8 V
±5.0 ±5.5 V
28 100 mA
2 _______________________________________________________________________________________
+3V-Powered, Low-Power,
True RS-232 Transceiver
TIMING CHARACTERISTICS
(VCC= 3.0V to 3.6V, TA= T
PARAMETER MIN TYP MAX UNITS
Data Rate 120 250 kbps
Receiver Output Enable Time 70 200 ns
Receiver Output Disable Time 420 700 ns
Transmitter Output Enable Time
Transmitter Output Disable Time 600 ns
Receiver Propagation Delay
Transmitter Propagation Delay
Transition-Region Slew Rate
MIN
to T
, unless otherwise noted.)
MAX
SYMBOL
t
ER
t
DR
t
ET
t
DT
t
PHLR
t
PLHR
t
PHLT
t
PLHT
CONDITIONS
1000pF 3kΩ load on each transmitter,
150pF load on each receiver
Includes power-supply start-up
2500pF 3kΩ load
RL= 3kΩ to 7kΩ, CL= 50pF to 2500pF,
measured from +3V to -3V or -3V to +3V
250 µs
300 700
300 700
800 2000
800 2000
ns150pF load
ns
4.0 10 30 V/µs
__________________________________________Typical Operating Characteristics
(VCC= 3.3V, TA = +25°C, unless otherwise noted.)
SUPPLY POWER vs.
180
ALL TRANSMITTERS
LOADED w/ 3kΩ AND
160
STATED CAPACITANCE
3 TRANSMITTERS
140
AT DATA RATE
3 TRANSMITTERS,
120
1 AT DATA RATE,
1 LOW, 1 HIGH
100
SUPPLY POWER (mW)
80
60
0204060
DATA RATE
DATA RATE (kbps)
212 GR4
2500pF
1000pF
2500pF
1000pF
120
100
80
TRANSMITTER OUTPUT VOLTAGE vs.
DATA RATE
6
4
2
0
-2
OUTPUT VOLTAGE (V)
-4
-6
0 50 100 150
5000pF
ALL TRANSMITTERS
LOADED SIMULTANEOUSLY
w/ SPECIFIED CAPACITANCE AND 3kΩ
5000pF
4000pF
2500pF
1000pF
DATA RATE (kbps)
4000pF
2500pF
1000pF
200
212 GR5
250
MAX212
_______________________________________________________________________________________ 3
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