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MAX218CWP
Datasheet
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Maxim MAX218CWP, MAX218CPP, MAX218CAP, MAX218EAP, MAX218C-D Datasheet

...
19-0246; Rev 1; 7/95
1.8V to 4.25V-Powered,
True RS-232 Dual Transceiver
_______________General Description
The MAX218 RS-232 transceiver is intended for battery­powered EIA/TIA-232E and V.28/V.24 communications interfaces that need two drivers and two receivers with minimum power consumption. It provides a wide +1.8V to +4.25V operating voltage range while maintaining true RS-232 and EIA/TIA-562 voltage levels. The MAX218 runs from two alkaline, NiCd, or NiMH cells without any form of voltage regulator.
A guaranteed 120kbps data rate provides compatibility with popular software for communicating with personal computers. Three-state drivers are provided on all receiver outputs so that multiple receivers, generally of different interface standards, can be wire-ORed at the UART. The MAX218 is available in 20-pin DIP, SO, and SSOP packages.
________________________Applications
Battery-Powered Equipment Computers Printers Peripherals Instruments Modems
____________________________Features
BETTER THAN BIPOLAR! ♦ Operates Directly from Two Alkaline, NiCd,
or NiMH Cells
♦ +1.8V to +4.25V Supply Voltage Range ♦ 120kbps Data Rate ♦ Low-Cost Surface-Mount Components ♦ Meets EIA/TIA-232E Specifications ♦ 1µA Low-Power Shutdown Mode ♦ Both Receivers Active During Low-Power Shutdown ♦ Three-State Receiver Outputs ♦ Flow-Through Pinout ♦ On-Board DC-DC Converters ♦ 20-Pin SSOP, Wide SO, or DIP Packages
______________Ordering Information
PART TEMP. RANGE
MAX218CPP 0°C to +70°C MAX218CWP 0°C to +70°C 20 Wide SO MAX218CAP 0°C to +70°C 20 SSOP MAX218C/D 0°C to +70°C Dice* MAX218EPP -40°C to +85°C MAX218EWP -40°C to +85°C 20 Wide SO MAX218EAP -40°C to +85°C 20 SSOP
*Contact factory for dice specifications.
PIN-PACKAGE
20 Plastic DIP
20 Plastic DIP
MAX218
__________Typical Operating Circuit
1
19
V+
1.8V
4.25V
ON/OFF
ENABLE
TO
LX
6
V
CC
MAX218
3
SHDN T1IN
7
8 9
10
________________________________________________________________
T2IN R1OUT
R2OUT
T1
T2
R1
R2
EN
4
GND
C1+
C1-
T1OUT
T2OUT
R1IN
R2IN
5, 17, 20
15
V-
18 16
14
13 12
11
__________________Pin Configuration
TOP VIEW
N.C.
SHDN
GND
V T1IN T2IN
R1OUT R2OUT
LX
1 2 3
EN
4 5 6
CC
7 8 9
10
MAX218
DIP/SO/SSOP
Maxim Integrated Products
Call toll free 1-800-998-8800 for free samples or literature.
GND
20
V+
19
C1+
18
GND
17
C1-
16
V-
15
T1OUT
14
T2OUT
13
R1IN
12
R2IN
11
1
1.8V to 4.25V-Powered, True RS-232 Dual Transceiver
ABSOLUTE MAXIMUM RATINGS
Supply Voltages
....................................................................-0.3V to +4.6V
V
CC
V+.......................................................... (V
V-.......................................................................+0.3V to -7.4V
to V-..........................................................................+12V
V
CC
LX ................................................................-0.3V to (1V + V+)
Input Voltages
MAX218
T_IN, EN, S—H—D—N–................................................. -0.3V to +7V
R_IN.................................................................................±25V
Output Voltages
T_OUT.............................................................................±15V)
R_OUT....................................................-0.3V to (V
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 +7.5V
CC
CC
+ 0.3V)
ELECTRICAL CHARACTERISTICS
(Circuit of Figure 1, VCC= 1.8V to 4.25V, C1 = 0.47µF, C2 = C3 = C4 = 1µF, L1 = 15µH, TA= T Typical values are at V
DC CHARACTERISTICS
Shutdown Supply Current
LOGIC
Input Logic Threshold Low Input Logic Threshold High
EIA/TIA-232E RECEIVER INPUTS
Input Threshold Low
Input Threshold High
EIA/TIA-232E TRANSMITTER OUTPUTS
Note 1: Entire supply current for the circuit of Figure 1.
= 3.0V, TA= +25°C.)
CC
No load, VCC= EN = S—H—D—N–= 3.0V, TA= +25°C S—H—D—N–= EN = 0V, all R_INs static S—H—D—N–= 0V, EN = VCC, all R_INs static
T_IN, EN, S—H—D—N T_IN, EN, S—H—D—N T_IN T_IN, EN, S—H—D—N–= 0V or V R_OUT, I R_OUT, I R_OUT, 0V ≤ R_OUT ≤ VCC, EN = 0V
VCC= 2.0V to 4.25V VCC= 1.8V to 4.25V VCC= 1.8V to 4.25V VCC= 1.8V to 3.6V
-15V < R_IN < +15V
All transmitter outputs loaded with 3kΩ to ground VCC= 0V, -2V < T_OUT < +2V
OUT OUT
CONDITIONS
– –
CC
= 1.0mA
= -0.4mA
Short-Circuit Duration, R_OUT, T_OUT to GND ....... Continuous
Continuous Power Dissipation (T
Plastic DIP (derate 11.11mW/°C above +70°C) ..........889mW
Wide SO (derate 10.00mW/°C above +70°C)..............800mW
SSOP (derate 8.00mW/°C above +70°C) ...................640mW
Operating Temperature Ranges
MAX218C_ P..................................................... 0°C to +70°C
MAX218E_ P................................................... -40°C to +85°C
Storage Temperature Range ........................... -65°C to +150°C
Lead Temperature (soldering, 10sec) ........................... +300°C
CC
0.4
0.3
= +70°C)
A
to T
MIN
MAX
0.04 10
0.04 10
, unless otherwise noted.
UNITSMIN TYP MAXPARAMETER
CC
3.0
2.8
V1.8 4.25Operating Voltage Range
mA1.9 3.0Supply Current (Note 1)
µA
V0.33 x V V0.67 x V V0.1Input Hysteresis
µA0.001 ±1Input Leakage Current
V0.4Output Voltage Low VVCC- 0.25 VCC- 0.08Output Voltage High
µA0.05 ±10Output Leakage Current
V-25 +25Input Voltage Range V
V V0.7Input Hysteresis
kΩ357Input Resistance
V±5 ±6Output Voltage Swing Ω300Output Resistance
mA±24 ±100Output Short-Circuit Current
2 _______________________________________________________________________________________
1.8V to 4.25V-Powered,
True RS-232 Dual Transceiver
TIMING CHARACTERISTICS
(Circuit of Figure 1, VCC= 1.8V to 4.25V, C1 = 0.47µF, C2 = C3 = C4 = 1µF, L1 = 15µH, TA= T Typical values are at V
Receiver Output Enable Time Receiver Output Disable Time Transmitter Output Enable Time Transmitter Output Disable Time
Receiver Propagation Delay
Transmitter Propagation Delay
= 3.0V, TA= +25°C.)
CC
SYMBOLPARAMETER
CONDITIONS
1000pF || 3kΩ load each transmitter, 150pF load each receiver
ER DR ET DT
150pF load
PHLR
150pF load
PLHR
2500pF || 3kΩ load
PHLT
2500pF || 3kΩ load
PLHT
TA= +25°C, VCC= 3.0V, RL= 3kΩ to 7kΩ, CL= 50pF to 2500pF, measured from +3V to -3V or -3V to +3V
to T
MIN
MIN TYP MAX
, unless otherwise noted.
MAX
290 700t 260 700t
1.9 2.7t
1.8 2.7t
UNITS
kbps120Data Rate
ns90 300t ns200 500t µs140 450t ns500t
ns
µs
V/µs3.0 30Transition Region Slew Rate
______________________________________________________________Pin Description
PIN
Inductor/Diode Connection PointLX1 Not internally connectedN.C.2
–
3
6
S—H—D—N
EN4
V
CC
R1OUT, R2OUT9, 10
Shutdown Control. Connect to VCCfor normal operation. Connect to GND to shut down the power supply and to disable the drivers. Receiver status is not changed by this control.
Receiver Output Enable Control. Connect to VCCfor normal operation. Connect to GND to force the receiver outputs into high-Z state.
Ground. Connect all GND pins to ground.GND5, 17, 20 Supply Voltage Input; 1.8V to 4.25V. Bypass to GND with at least 1µF. See
Selection
Transmitter InputsT1IN, T2IN7, 8 Receiver Outputs; swing between GND and V Receiver InputsR2IN, R1IN11, 12 Transmitter Outputs; swing between V+ and V-.T2OUT, T1OUT13, 14 Negative Supply generated on-boardV-15 Terminals for Negative Charge-Pump CapacitorC1-, C1+16, 18 Positive Supply generated on-boardV+19
section.
FUNCTIONNAME
Capacitor
CC.
MAX218
_______________________________________________________________________________________ 3
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