+5V-Powered, Multichannel RS-232
Drivers/Receivers
ELECTRICAL CHARACTERISTICS—MAX225/MAX244–MAX249 (continued)
(MAX225, V
CC
= 5.0V ±5%; MAX244–MAX249, V
CC
= +5.0V ±10%, external capacitors C1–C4 = 1µF; T
A
= T
MIN
to T
MAX
; unless oth-
erwise noted.)
PARAMETER
POWER SUPPLY AND CONTROL LOGIC
Operating Supply Voltage
No load
V
CC
Supply Current
(Normal Operation)
3kΩ loads on
all outputs
T
A
= +25°C
T
A
= T
MIN
to T
MAX
Leakage current
Control Input
AC CHARACTERISTICS
Transition Slew Rate
Transmitter Propagation Delay
TLL to RS-232 (Normal Operation),
Figure 1
Receiver Propagation Delay
TLL to RS-232 (Normal Operation),
Figure 2
Receiver Propagation Delay
TLL to RS-232 (Low-Power Mode),
Figure 2
Transmitter + to - Propagation
Delay Difference (Normal Operation)
Receiver + to - Propagation
Delay Difference (Normal Operation)
C
L
= 50pF to 2500pF, R
L
= 3kΩ to 7kΩ, V
CC
= 5V,
T
A
= +25°C, measured from +3V to -3V or -3V to +3V
t
PHLT
t
PLHT
t
PHLR
t
PLHR
t
PHLS
t
PLHS
t
PHLT
- t
PLHT
t
PHLR
- t
PLHR
5
10
1.3
1.5
0.6
0.6
0.6
3.0
350
350
100
100
MAX246–MAX249
(excludes charge-pump startup)
Transmitter Enable Time
t
ET
MAX225/MAX245–MAX249
(includes charge-pump startup)
5
10
100
500
500
30
3.5
µs
3.5
1.5
µs
1.5
10
µs
10
ns
ns
ns
ns
µs
ms
ns
V/µs
Threshold low
Threshold high
2.4
1.4
1.4
MAX225
MAX244–MAX249
MAX225
MAX244–MAX249
MAX225
MAX244–MAX249
4.75
4.5
10
11
40
57
8
25
50
±1
0.8
µA
µA
V
5.25
5.5
20
30
mA
V
CONDITIONS
MIN
TYP
MAX
UNITS
MAX220–MAX249
Shutdown Supply Current
Receiver-Output Enable Time, Figure 3 t
ER
Receiver-Output Disable Time, Figure 3 t
DR
Transmitter Disable Time, Figure 4
t
DT
Note 7:
The 300Ω minimum specification complies with EIA/TIA-232E, but the actual resistance when in shutdown mode or V
CC
=
0V is 10MΩ as is implied by the leakage specification.
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9
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
