ISL4238E Intersil Corporation, ISL4238E Datasheet - Page 8

• Manufacturer Part Number: ISL4238E
• Description: QFN Packaged, 15kV Esd Protected, +2.7V to +5.5V, 10Nanoamp, 250kbps/ 1Mbps, RS-232 Transceivers With Enhanced Automatic Powerdown
• Manufacturer: Intersil Corporation

Electrical Specifications
NOTES:
Detailed Description
These interface ICs operate from a single +2.7V to +5.5V
supply, guarantee a 250kbps (ISL4238E/44E) / 1Mbps
(ISL4245E) minimum data rate, require only four small
external 0.1µF capacitors, feature low power consumption,
and meet all ElA RS-232C and V.28 specifications. The
circuit is divided into three sections: The charge pump, the
transmitters, and the receivers.
Charge-Pump
Intersil’s new RS-232 family utilizes regulated on-chip dual
charge pumps as voltage doublers, and voltage inverters to
generate ±5.5V transmitter supplies from a V
low as 3.0V. This allows these devices to maintain RS-232
compliant output levels over the ±10% tolerance range of
3.3V powered systems. The efficient on-chip power supplies
require only four small, external 0.1µF capacitors for the
voltage doubler and inverter functions. The charge pumps
operate discontinuously (i.e., they turn off as soon as the V+
and V- supplies are pumped up to the nominal values),
resulting in significant power savings.
Receiver Output Enable Time
Receiver Output Disable Time
Transmitter Output Enable Time
ISL4238E/44E/45E
Transmitter Output Disable Time
ISL4238E/44E/45E
Transition Region Slew Rate
ISL4238E/44E
Transition Region Slew Rate
ISL4245E
ESD PERFORMANCE
RS-232 Pins (T
All Other Pins
4. ISL4238E inputs utilize a positive feedback resistor. The input current is negligible when the input is at either supply rail.
5. An “edge” is defined as a transition through the transmitter or receiver input thresholds.
6. Skew is measured at the receiver input switching points (1.4V).
7. Skew is measured at the transmitter zero crossing points.
PARAMETER
OUT
, R
IN
)
8
Test Conditions: ISL4238E V
ISL424XE V
Normal Operation, R
Normal Operation, R
Normal Operation, R
Normal Operation, R
V
R
Measured From 3V to -3V
or -3V to 3V
V
-3V or -3V to 3V, C
Human Body Model
IEC6100-4-2 Air Gap Discharge
IEC6100-4-2 Contact Discharge
Human Body Model
CC
CC
L
= 3kΩ to 7kΩ,
= 3V to 3.6V,
= 3V to 3.6V, R
CC
ISL4238E, ISL4244E, ISL4245E
CC
= 3V to 5.5V, C
supply as
TEST CONDITIONS
L
L
L
L
L
L
= 150pF to 1000pF
= 3kΩ to 7kΩ, Measured From 3V to
= 1kΩ to 0.5V
= 1kΩ to 0.5V
= 3kΩ, C
= 3kΩ, C
CC
C
C
1
L
L
= 3.15V to 5.5V, C
L
L
- C
= 150pF to 1000pF
= 150pF to 2500pF
= 1000pF
= 1000pF
4
CC
CC
= 0.1
, C
, C
Transmitters
The transmitters are proprietary, low dropout, inverting
drivers that translate TTL/CMOS inputs to EIA/TIA-232
output levels. Coupled with the on-chip ±5.5V supplies,
these transmitters deliver true RS-232 levels over a wide
range of single supply system voltages.
Transmitter outputs disable and assume a high impedance
state when the device enters the powerdown mode (see
Table 2). These outputs may be driven to ±12V when
disabled.
The ISL4238E/44E guarantee a 250kbps data rate for full
load conditions (3kΩ and 1000pF), V
transmitter operating at full speed. Under more typical
conditions of V
transmitter easily operates at 1Mbps.
The ISL4245E guarantees a 1Mbps data rate for full load
conditions (3kΩ and 250pF), V
transmitter operating at full speed. Under more typical
conditions of V
transmitter easily operates at 1.4Mbps.
µ
L
L
F; Unless Otherwise Specified. Typicals are at T
= 15pF
= 15pF
1
- C
4
= 0.1
CC
CC
TEMP
µ
(
≥ 3.3V, R
≥ 3.3V, R
Full
Full
Full
Full
Full
Full
Full
o
25
25
25
25
25
25
25
25
25
25
25
F; V
C)
CC
= 3V, C
MIN
L
L
24
24
6
6
4
4
-
-
-
-
-
-
-
-
-
-
-
-
= 3kΩ, and C
= 3kΩ, and C
CC
1
≥ 3.0V, with one
- C
TYP
CC
200
200
350
400
±15
±15
2.5
2.7
4
25
35
11
10
40
35
±8
±3
9
8
= 0.22
≥ 3.0V, with one
L
L
µ
= 250pF, one
= 250pF, one
A
MAX
F;
350
400
500
600
150
150
= 25
40
50
30
30
30
30
4
4
-
-
-
-
o
C
UNITS
V/µs
V/µs
V/µs
V/µs
V/µs
V/µs
kV
kV
kV
kV
ns
ns
ns
ns
µs
µs
µs
µs