Datasheet ICL3237E Datasheet (intersil)

®

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ICL3237E

Data Sheet July 2004

±15kV ESD Protected, 10nA Supply­Current, +3V to +5.5V, 250k/1Mbps,
RS-232 Transmitters/Receivers

The Intersil ICL3237E contains 3.0V to 5.5V powered
RS-232 transmitters/receivers which meet ElA/TIA-232 and
V.28/V.24 specifications, even at V
provides
Human Body Model) on transmitter outputs and receiver
inputs (RS-232 pins). Targeted applications are cell phones,
PDAs, P almtops , and notebook and laptop computers where
the low operational, and even lower standby, power
consumption is critical. Efficient on-chip charge pumps,
coupled with the manual powerdown function, reduce the
standby supply current to a 10nA trickle. Small footprint
packaging, and the use of small, low value capacitors ensure
board space savings as well. Data rates greater than 1Mbps
(MBAUD = V
conditions. The ICL3237E is fully compatible with 3.3V only
systems, mixed 3.3V and 5.0V systems, and 5.0V only
systems.

The ICL3237E is a 5 driver, 3 receiver device that also
includes a noninverting always-active receiver for “wake-up”
capability.

Table 1 summarizes the features of the device represented
by this data sheet, while Application Note AN9863
summarizes the features of each device comprising the
ICL32XX 3V family.

NOTE:

1. Data rate is selectable via the MBAUD pin.

±15kV ESD protection (IEC61000-4-2 Air Gap and

) are guaranteed at worst case load

CC

PART

NUMBER

ICL3237E 5 3 1 250/1000 YES NO YES NO

NO. OF

Tx.

NO. OF

Rx.

= 3.0V. Additionally, it

CC

TABLE 1. SUMMARY OF FEATURES

NO. OF

MONITOR Rx.

)

(R

OUTB

(NOTE 1)

DATA
RATE

(kbps)

Features

• ESD Protection For RS-232 I/O Pins to ±15kV (IEC61000)

• Pin Compatible Replacement for MAX3237E

• Pin Selectable, Guaranteed Data Rate . . 250kbps/1Mbps

• Meets EIA/TIA-232 and V.28/V.24 Specifications at 3V

• RS-232 Compatible with VCC = 2.7V

• Latch-Up Fre e

• On-Chip Voltage Converters Require Only Four External
Capacitors

• Manual Powerdown Feature

• Flow Through Pinout

• Rx and Tx Hysteresis For Improved Noise Immunity

• Rx Active in Powerdown; Separate Rx Enable Pin

• Guaranteed Minimum Slew Rate. . . . . . . 6V/µs or 24V/µs

• Wide Power Supply Range. . . . . . . . Single +3V to +5.5V

• Low Supply Current in Powerdown State. . . . . . . . . .10nA

• Pb-free available

Applications

• Any System Requiring RS-232 Communication Ports

- Battery Powered, Hand-Held, and Portable Equipment

- Laptop Computers, Notebooks, Palmtops

- Modems, Printers and other Peripherals

- Data Cradles and Cables

- Cellular/Mobile Phone

Rx. ENABLE
FUNCTION?

READY

OUTPUT?

MANUAL

POWER-

DOWN?

FN6014.2

AUTOMATIC

POWERDOWN

FUNCTION?

1

Copyright © Intersil Americas Inc. 2002-2004. All Rights Reserved All other trademarks mentioned are the property of their respective owners.

CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.

1-888-INTERSIL or 321-724-7143

| Intersil (and design) is a registered trademark of Intersil Americas Inc.

ICL3237E

www.BDTIC.com/Intersil

Pinout

Ordering Information

TEMP.

PART NUMBER

RANGE (oC) PACKAGE

ICL3237ECA 0 to 70 28 Ld SSOP M28.209
ICL3237ECAZ

(See Note)

0 to 70 28 Ld SSOP

(Pb-free)
ICL3237EIA -40 to 85 28 Ld SSOP M28.209
ICL3237EIAZ

(See Note)

-40 to 85 28 Ld SSOP
(Pb-free)

*Add “-T” suffix to part number for tape and reel packaging.

NOTE: Intersil Pb-free products employ special Pb-free material
sets; molding compounds/die attach materials and 100% matte tin
plate termination finish, which is compatible with both SnPb and
Pb-free soldering operations. Intersil Pb-free products are MSL
classified at Pb-free peak reflow temperatures that meet or exceed
the Pb-free requirements of IPC/JEDEC J Std-020B.

PKG. DWG.

#

M28.209

M28.209

C2+

GND

C2-

T1

OUT

T2

OUT

T3

OUT

R1
R2

T4

OUT

R3

T5

OUT

SHDN

ICL3237E (SSOP)

1
2
3

V-

4
5
6
7
8

IN

9

IN

10
11

IN

12

EN

13
14

TOP VIEW

28
27
26
25
24
23
22
21
20
19
18
17
16
15

C1+
V+
V

CC

C1­T1

IN

T2

IN

T3

IN

R1

OUT

R2

OUT

T4

IN

R3

OUT

T5

IN

R1

OUTB

MBAUD

Pin Descriptions

PIN FUNCTION

V

CC

V+ Internally generated positive transmitter supply (+5.5V).

V- Internally generated negative transmitter supply (-5.5V).

GND Ground connection.

C1+ External capacitor (voltage doubler) is connected to this lead.

C1- External capacitor (voltage doubler) is connected to this lead.

C2+ External capacitor (voltage inverter) is connected to this lead.

C2- External capacitor (voltage inverter) is connected to this lead.
T

T

OUT

R

R

OUT

R

OUTB

EN

SHDN

MBAUD Input low selects 250kbps data rate, and input high selects 1Mbps data rate (Note 2).

NOTE:

2. These input pins incorporate positive feedback resistors. Once the input is driven to a valid logic level, the feedback resistor maintains that logic
level until V

System power supply input (3.0V to 5.5V).

TTL/CMOS compatible transm it ter I nputs (Note 2).

IN

±15kV ESD Protected, RS-232 level (nominally ±5.5V) transmitter outputs.
±15kV ESD Protected, RS-232 compatible receiver in puts.

IN

TTL/CMOS level receiver outputs.
TTL/CMOS level, noninverting, always enabled receiver output.
Active low receiver enable control; doesn’t disable R

output (Note 2).

OUTB

Active low input to shut down transmitters and on-board power supply, to place device in low power mode (Note 2).

is removed.

CC

2

Typical Operating Circuit

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NOTE 4

TTL/CMOS

LOGIC LEVELS

+3.3V

0.1µF

0.1µF

R1

ICL3237E

ICL3237E

+

0.1µF

28

C

1

C

2

T1

T2

T3

T4

T5

OUTB

IN

IN

IN

IN

IN

C1+

+

25

C1-

1

C2+

+

3

C2-

24

23

22 7

19 10

17 12

16

V

CC

C3 (OPTIONAL CONNECTION, NOTE 3)

V+

V-

+

27

C

3

+

0.1µF

C

0.1µF

+

T1

T2

T3

T4

T5

4

OUT

OUT

OUT

OUT

OUT

NOTE 4

RS-232
LEVELS

4

5

6

26

T

1

T

2

T

3

T

4

T

5

NOTES:

3. THE NEGATIVE TERMINAL OF C

4. FOR V

= 3.15V (3.3V -5%), USE C1 - C4 = 0.1µF OR GREATER. FOR VCC = 3.0V (3.3V -10%), USE C1 - C4 = 0.22µF.

CC

R1

R2

R3

TO CONTROL LOGIC

CAN BE CONNECTED TO EITHER VCC OR GND.

3

21

OUT

R

1

OUT

R

2

OUT

R

3

EN

13

14

V

CC

15

SHDN

MBAUD

GND

8

R1

IN

5kΩ

920

R2

5kΩ

1118

R3

5kΩ

2

RS-232

IN

LEVELS

IN

3

ICL3237E

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Absolute Maximum Ratings Thermal Information

VCC to Ground. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 6V

V+ to Ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 7V

V- to Ground. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +0.3V to -7V

V+ to V- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14V

Input Voltages

, EN, SHDN, MBAUD . . . . . . . . . . . . . . . . . . . . . . -0.3V to 6V

T

IN

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±25V

R

IN

Output Voltages

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±13.2V

T

OUT

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to VCC +0.3V

R

OUT

Short Circuit Duration

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Continuous

T

OUT

ESD Rating . . . . . . . . . . . . . . . . . . . . . . . . . See Specification Table

CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the
device at these or any other conditions above those indicated in the operational sections of this specification is not implied.

NOTE:

5. θ

is measured with the component mounted on a low effective thermal conductivity test board in free air. See Tech Brief TB379 for details.

JA

Thermal Resistance (Typical, Note 5)

28 Ld SSOP Package . . . . . . . . . . . . . . . . . . . . . . . 100

Moisture Sensitivity (see Technical Brief TB363)

SSOP Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Level 1

Maximum Junction Temperature (Plastic Package) . . . . . . . 150

Maximum Storage Temperature Range. . . . . . . . . . -65

Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . 300

(Lead Tips Only)

θ

(oC/W)

JA

o

C to 150oC

Operating Conditions

Temperature Range

ICL3237EC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0

ICL3237EI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -40

o

C to 70oC

o

C to 85oC

o

o

C

C

Electrical Specifications Test Conditions: V

Specified. Typicals are at T

PARAMETER TEST CONDITIONS

DC CHARACTERISTICS

Supply Current,
Powerdown Disabled

Supply Current, Powerdown SHDN

LOGIC AND TRANSMITTER INPUTS AND RECEIVER OUTPUTS

Input Logic Threshold Low T
Input Logic Threshold High T

Transmitter Input Hysteresis 25 - 0.5 - V
Input Leakage Current T
Output Leakage Current EN
Output Voltage Low I
Output Voltage High I

RECEIVER INPUTS

Input Voltage Range Full -25 - 25 V
Input Threshold Low V

Input Threshold High V
Input Hysteresis 25 - 0.5 - V
Input Resistance 25 3 5 7 kΩ

TRANSMITTER OUTPUTS

Output Voltage Swing All Transmitter Outputs Loaded with 3kΩ to Ground Full ±5.0 ±5.4 - V
Output Resistance V
Output Short-Circuit Current Full - ±35 ±60 mA
Output Leakage Current V

All Outputs Unloaded, V

= GND 25 - 10 300 nA

, EN, SHDN, MBAUD Full - - 0.8 V

IN

, EN, SHDN,

IN

MBAUD

, EN, SHDN, MBAUD (Note 7) Full - ±0.01 ±1.0 µA

IN

=V

(Receivers Disabled) Full - ±0.05 ±10 µA

CC

= 1.6mA Full - - 0.4 V

OUT

= -1.0mA Full V

OUT

= 3.3V 25 0.6 1.2 - V

CC

V

= 5.0V 25 0.8 1.5 - V

CC

= 3.3V to 5.0V 25 - 1.6 2.4 V

CC

= V+ = V- = 0V, Transmitter Output = ±2V Full 300 10M - Ω

CC

= ±12V, VCC= 0V or 3V to 5.5V, SHDN =GND Full - - ±25 µA

OUT

= 3.15V to 5.5V, C1 - C4 = 0.1µF; VCC = 3V, C1 - C4 = 0.22µF, Unless Otherwise

CC

= 25oC

A

TEMP

o

C) MIN TYP MAX UNITS

(

= 3.15V, SHDN =V

CC

VCC = 3.3V Full 2.0 - - V
V

= 5.0V Full 2.4 - - V

CC

CC

25 - 0.3 1.0 mA

CC

-0.6 V

-0.1 - V

CC

4

ICL3237E

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Electrical Specifications Test Conditions: V

Specified. Typicals are at T

PARAMETER TEST CONDITIONS

TIMING CHARACTERISTICS

Maximum Data Rate R

Receiver Propagation Delay Receiver Input to

Receiver Output Enable Time Normal Operation 25 - 200 - ns
Receiver Output Disable Time Normal Operation 25 - 200 - ns
Transmitter Skew t

Receiver Skew t
Transition Region Slew Rate V

ESD PERFORMANCE

RS-232 Pins (T

All Other Pins Human Body Model 25 - ±2.5 - kV

NOTES:

6. Skew is measured at the input switching points (1.4V).

7. These inputs utilize a positive feedback resistor. The input current is negligible when the input is at either supply rail.

, RIN) Human Body Model 25 - ±15 - kV

OUT

=3kΩ, One

L

Transmitter Switching

Receiver Output,

= 150pF

C

L

- t

PHL

PHL

CC

R

L

Measured From 3V to

-3V or -3V to 3V

IEC61000-4-2 Air Gap Discharge 25 - ±15 - kV
IEC61000-4-2 Contact Discharge 25 - ±8-kV

Note 6 MBAUD = GND 25 - 100 ns

PLH,

- t

, CL = 150pF 25 - 50 - ns

PLH

=3.3V,

=3kΩ to 7kΩ,

= 3.15V to 5.5V, C1 - C4 = 0.1µF; VCC = 3V, C1 - C4 = 0.22µF, Unless Otherwise

CC

= 25oC (Continued)

A

TEMP

o

(

C) MIN TYP MAX UNITS

CL= 1000pF MBAUD = GND Full 250 700 - kbps
V

= 3V to 4.5V,

CC

= 250pF

C

L

= 4.5V to 5.5V,

V

CC

= 1000pF

C

L

t

PHL

t

PLH

MBAUD = V

= 150pF to 1000pF MBAUD = GND 25 6 17 30 V/µs

C

L

C

= 150pF to 2500pF MBAUD = GND 25 4 12 30 V/µs

L

, VCC = 3.0V 25 - 25 ns

CC

MBAUD = V

MBAUD = V

MBAUD = V

Full 1000 1700 - kbps

CC

Full 1000 1100 - kbps

CC

25 - 0.15 - µs
25 - 0.15 - µs

25 24 40 150 V/µs

CC

5

ICL3237E

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Detailed Description

The ICL3237E operates from a single +3V to +5.5V supply,
guarantees a 1Mbps minim um data rate (MBAUD = V
requires only four small external 0.1µF (0.22µF f o r
V

= 3.0V) capacitors, features low power consumption,

CC

and meets all EIA/TIA-232 and V . 28 specifications. The
circuit is divided into three sections: The charge pump, the
transmitters, and the receivers.

Charge-Pump

Intersil’s new ICL32XX family utilizes regulated on-chip dual
charge pumps as voltage doublers, and voltage inverters to
generate ±5.5V transmitter supplies from a V

supply as

CC

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 at V

=3.3V. See

CC

the “Capacitor Selection” section, and Table 3 for capacitor
recommendations for other operating conditions. The cha rge
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.

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.

All 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 ICL3237E guarantees a 1Mbps data rate
(MBAUD = V
V

≥ 3.0V, with one transmitter operating at full speed.

CC

Under more typical conditions of V
R

=3kΩ, and CL= 250pF, one transmitter easily operates

L

at 1.7Mbps.
Transmitter inputs incorporate an active positive feedback

resistor that maintains the last driven input state in the
absence of a forcing signal. Unused transmitter inputs may
be left unconnected.

) for full load conditions (3kΩ and 250pF),

CC

≥ 3.3V, C

CC

1-4

),

CC

= 0.1µF,

hysteresis to increase noise immunity and decrease errors
due to slow input signal transitions.

Monitor receivers remain active even during manual
powerdown and forced receiver disable, making them
extremely useful for Ring Indicator monitoring. Standard
receivers driving powered down peripherals must be
disabled to prevent current flow through the peripheral’s
protection diodes (see Figures 2 and 3). This renders them
useless for wake up functions, but the corresponding monitor
receiver can be dedicated to this task as shown in Figure 3.

V

CC

R

XIN

-25V ≤ V

FIGURE 1. INVERTING RECEIVER CONNECTIONS

RIN

≤ +25V

GND

5kΩ

R

GND ≤ V

XOUT

ROUT

≤ V

CC

Po werdown Functionality

This 3V device requires a nominal supply current of 0.3mA
during normal operation (not in powerdown mode). This is
considerably less than the 5mA to 11mA current required of
5V RS-232 devices. The already low current requirement
drops significantly when the device enters powerdown mode.
In powerdown, supply current drops to 10nA, because the
on-chip charge pump turns off (V+ collapses to V
collapses to GND), and the transmitter outputs tristate. This
micro-power mode makes the ICL3237E ideal for battery
powered and portable applications.

Software Controlled (Manual) Powerdown

On the ICL3237E, the powerdown control is via a simple
shutdown (SHDN
operation, while driving it low forces the IC into it’s
powerdown state. Connect SHDN
function isn’t needed. Note that all the receiver outputs
remain enabled during shutdown (see Table 2). For the
lowest power consumption during powerdown, the receivers
should also be disabled by driving the EN
next section, and Figures 2 and 3). The time required to exit
powerdown, and resume transmission is only 100µs.

) pin. Driving this pin high enables normal

to VCC if the powerdown

input high (see

CC

, V-

Receivers

The ICL3237E contains standard inverting receivers that
tristate only when the EN

control line is driven high.
Additionally, it includes a noninverting (monitor) receiver
(denoted by the R

label) that is always active,

OUTB

regardless of the state of any control lines. All the receivers
convert RS-232 signals to CMOS output levels and accept
inputs up to ±25V while presenting the required 3kΩ to 7kΩ
input impedance (see Figure 1) even if the power is off
(V

= 0V). The receivers’ Schmitt trigger input stage uses

CC

6

ICL3237E

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TABLE 2. POWERDOWN AND ENABLE LOGIC TRUTH TABLE

INPUT EN INPUT TRANSMITTER OUTPUTS RECEIVER OUTPUTS R

SHDN

L L High-Z Active Active Manual Powerdown
L H High-Z High-Z Active Manual Powerdown w/Rcvr. Disabled
H L Active Active Active Normal Operation
H H Active High-Z Active Normal Operation w/Rcvr. Disabled

OUTPUT MODE OF OPERATION

OUTB

V

CC

V

CC

V

OUT = VCC

Rx

POWERED

DOWN

UART

Tx

= GND

GND

FIGURE 2. POWER DRAIN THROUGH POWERED DO WN

PERIPHERAL

TO

WAKE-UP

LOGIC

V

CC

R

X

POWERED

DOWN

UART

FIGURE 3. DISABLED RECEIVERS PREVENT POWER DRAIN

T

X

SHDN

SHDN

TRANSITION

DETECTOR

R1

V

OUT =

= GND, EN = V

V

OUTB

R1

CC

HI-Z

OUT

T1

IN

CC

V

CC

CURRENT
FLOW

OLD

RS-232 CHIP

ICL3237E

R1

T1

IN

OUT

Receiver ENABLE Control

This device also features an EN input to control the receiver
outputs. Driving EN
receiver outputs placing them in a high impedance state.
This is useful to eliminate supply current, due to a receiver
output forward biasing the protection diode, when driving the
input of a powered down (V
Figure 2). The enable input has no effect on transmitter nor
monitor (R

OUTB

high disables all the inverting (standard)

= GND) peripheral (see

CC

) outputs.

MegaBaud Selection

In normal operating mode (MBAUD = GND), the ICL3237E
transmitters guarantee a 250kbps data rate with worst-case
loads of 3kΩ in parallel with 1000pF. This provides
compatibility with PC-to-PC communication software, such
as Laplink™.

For higher speed serial communications, the ICL3237E
features MegaBaud operation. In MegaBaud operating mode
(MBAUD = V

), the ICL3237E transmitters guarantee a

CC

1Mbps data rate with worst-case loads of 3kΩ in parallel with
250pF for 3.0V < V

< 4.5V. For 5V ±10% operation, the

CC

ICL3237E transmitters guarantee a 1Mbps data rate with
worst-case loads of 3kΩ in parallel with 1000pF.

Capacitor Selection

The charge pumps require 0.1µF capacitors for 3.3V (5%
tolerance) operation. For other supply voltages refer to Table
3 for capacitor values. Do not use values smaller than those
listed in Table 3. Increasing the capacitor values (by a factor
of 2) reduces ripple on the transmitter outputs and slightly
reduces power consumption. C
increased without increasing C
increase C

without also increasing C2, C3, and C4 to

1

maintain the proper ratios (C

, C3, and C4 can be

2

’s value, however, do not

1

to the other capacitors).

1

When using minimum required capacitor values, make sure
that capacitor values do not degrade excessively with
temperature. If in doubt, use capacitors with a larger nominal
value. The capacitor’s equivalent series resistance (ESR)
usually rises at low temperatures and it influences the
amount of ripple on V+ and V-.

TABLE 3. REQUIRED CAPACITOR VALUES

V

CC

(V)

3.0 to 3.6 (3.3V ±10%) 0.22 0.22

3.15 to 3.6 (3.3V ±5%) 0.1 0.1

4.5 to 5.5 0.047 0.33

3.0 to 5.5 0.22 1.0

C

(µF)

1

C

2

, C3, C

(µF)

4

Po wer Supply Decoupling

In most circumstances a 0.1µF bypass capacitor is
adequate. In applications that are particularly sensitive to
power supply noise, decouple V
capacitor of the same value as the charge-pump capacitor C
Connect the bypass capacitor as close as possible to the IC.

to ground with a

CC

1

.

7

Laplink® is a registered trademark of Traveling Software.

ICL3237E

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Operation Down to 2.7V

ICL3237E transmitter outputs meet RS-562 levels (±3.7V), at
the full data rate, with V

as low as 2.7V. RS-562 levels

CC

typically ensure inter operability with RS-232 devices.

Transmitter Outputs when Exiting
Powerdown

Figure 4 shows the response of two transmitter outputs
when exiting powerdown mode. As they activate, the two
transmitter outputs properly go to opposite RS-232 levels,
with no glitching, ringing, nor undesirable transients. Each
transmitter is loaded with 3kΩ in parallel with 2500pF. Note
that the transmitters enable only when the magnitude of the
supplies exceed approximately 3V.

5V/DIV

2V/DIV

SHDN

T1

V

CC

0.1µF

+

C

1

+

C

2

V

CC

C1+

C1-

C2+

C2-

T

IN

R

OUT

EN

SHDN

+

V

CC

ICL3237E

V+

T

OUT

R

5k

MBAUD

V-

IN

FIGURE 5. TRANSMITTER LOOPBACK TEST CIRCUIT

5V/DIV.

MBAUD = GND

T1

IN

+

C

3

C

4

+

C

L

GND or V

CC

T2

VCC = +3.3V
C1 - C4 = 0.1µF

TIME (20µs/DIV.)

FIGURE 4. TRANSMITTER OUTPUTS WHEN EXITING

POWERDOWN

High Data Rates

The ICL3237E maintains the RS-232 ±5V minimum
transmitter output voltages even at high data rates. Figure 5
details a transmitter loopback test circuit, and Figure 6
illustrates the standard speed loopback test result for a
single transmitter driving 1000pF and an RS-232 load at
250kbps. Figure 7 shows the MegaBaud loopback results for
a single transmitter driving 250pF and an RS-232 load at
1Mbps. The static transmitters were also loaded with an
RS-232 receiver.

T1

OUT

R1

OUT

VCC = +3.3V
C1 - C4 = 0.1µF

2µs/DIV.

FIGURE 6. LOOPBACK TEST AT 250kbps (C

5V/DIV.

R1

T1

T1

OUT

OUT

MBAUD = V

IN

VCC = +3.3V
C1 - C4 = 0.1µF

CC

0.5µs/DIV.

FIGURE 7. LOOPBACK TEST AT 1Mbps (C

= 1000pF)

L

= 250pF)

L

8

ICL3237E

www.BDTIC.com/Intersil

Interconnection with 3V and 5V Logic

The ICL3237E directly interfaces with 5V CMOS and TTL
logic families. Nev ertheless, with the ICL32XX at 3.3V, and
the logic supply at 5V, AC, HC, and CD4000 outputs can
drive ICL32XX inputs, but ICL32XX outputs do not reach the
minimum V
information.

TABLE 4. LOGIC FAMILY COMPATIBILITY WITH VARIOUS

SYSTEM

POWER-SUPPLY

VOLTAGE

for these logic families. See Table 4 for more

IH

SUPPLY VOLTAGES

V

CC

SUPPLY

VOLTAGE

(V)

3.3 3.3 Compatible with all CMOS

5 5 Compatible with all TTL and

5 3.3 Compatible with ACT and HCT

(V) COMPATIBILITY

families.

CMOS logic families.

CMOS, and with TTL. ICL32XX
outputs are incompatible with AC,
HC, and CD4000 CMOS inputs.

±15kV ESD Protection

All pins on ICL32XX devices include ESD protection
structures, but the ICL32XXE family incorporates advanced
structures which allow the RS-232 pins (transmitter outputs
and receiver inputs) to survive ESD events up to ±15kV. The
RS-232 pins are particularly vulnerable to ESD damage
because they typically connect to an exposed port on the
exterior of the finished product. Simply touching the port
pins, or connecting a cable, can cause an ESD event that
might destroy unprotected ICs. These ne w ESD structures
protect the device whether or not it is powered up, protect
without allowing any latchup mechanism to activate, and
don’t interfere with RS-232 signals as large as ±25V.

Human Body Model (HBM) Testing

As the name implies, this test method emulates the ESD
event delivered to an IC during human handling. The tester
delivers the charge through a 1.5kΩ current limiting resistor,
making the test less severe than the IEC61000 test which
utilizes a 330Ω limiting resistor. The HBM method
determines an ICs ability to withstand the ESD transients
typically present during handling and manufacturing. Due to
the random nature of these events, each pin is tested with
respect to all other pins. The RS-232 pins on “E” family
devices can withstand HBM ESD events to ±15kV.

IEC61000-4-2 Testing

The IEC61000 test method applies to finished equipment,
rather than to an individual IC. Therefore, the pins most likely
to suffer an ESD event are those that are exposed to the
outside world (the RS-232 pins in this case), and the IC is
tested in its typical application configuration (power applied)
rather than testing each pin-to-pin combination. The lower
current limiting resistor coupled with the larger charge
storage capacitor yields a test that is much more severe than
the HBM test. The extra ESD protection built into this
device’s RS-232 pins allows the design of equipment
meeting level 4 criteria without the need for additional board
level protection on the RS-232 port.

AIR-GAP DISCHARGE TEST METHOD

For this test method, a charged probe tip moves toward the
IC pin until the voltage arcs to it. The current waveform
delivered to the IC pin depends on approach speed,
humidity, temperature, etc., so it is difficult to obtain
repeatable results.The “E” device RS-232 pins withstand
±15kV air-gap discharges.

CONTACT DISCHARGE TEST METHOD

During the contact discharge test, the probe contacts the
tested pin before the probe tip is energized, thereby
eliminating the variables associated with the air-gap
discharge. The result is a more repeatable and predictable
test, but equipment limits prevent testing de vices at voltages
higher than ±8kV. All “E” family devices survive ±8kV contact
discharges on the RS-232 pins.

9

ICL3237E

www.BDTIC.com/Intersil

Typical Performance Curves V

6

4

2

1 TRANSMITTER AT 250kbps
OTHER TRANSMITTERS AT 30kbps

0

MBAUD = GND

-2

-4

TRANSMITTER OUTPUT VOLTAGE (V)

-6
1000 2000 3000 4000 50000

LOAD CAPACITANCE (pF)

= 3.3V, TA = 25oC

CC

V

+

OUT

V

-

OUT

FIGURE 8. LOW SPEED TRANSMITTER OUTPUT VOLTA GE

vs LOAD CAPACITANCE

25

20

+SLEW

15

MBAUD = GND

6

4

2

1 TRANSMITTER AT 1Mbps
OTHER TRANSMITTERS AT 30kbps

0

MBAUD = V

-2

-4

TRANSMITTER OUTPUT VOLTAGE (V)

-6

CC

1000 2000 3000 4000 50000

LOAD CAPACITANCE (pF)

V

V

OUT

OUT

+

-

FIGURE 9. HIGH SPEED TRANSMITTER OUTPUT VOL TAGE

vs LOAD CAPACITANCE

90

MBAUD = V

70

50

+SLEW

CC

SLEW RATE (V/µs)

-SLEW

10

5

0 1000 2000 3000 4000 5000

LOAD CAPACITANCE (pF)

-SLEW

30

SLEW RATE (V/µs)

10

0

-SLEW

0 1000 2000 3000 4000 5000

LOAD CAPACITANCE (pF)

FIGURE 10. LOW SPEED SLEW RATE vs LOAD CAPACITANCE FIGURE 11. HIGH SPEED SLEW RATE vs LOAD

CAPACITANCE

SUPPLY CURRENT (mA)

90

80

70

60

50

40

30

20

0

MBAUD = V

1000

CC

250kbps

2000

LOAD CAPACITANCE (pF)

3000

1Mbps

120kbps

55

50

45

40

35

30

SUPPLY CURRENT (mA)

25

20

MBAUD = GND

0

1000

250kbps

2000

LOAD CAPACITANCE (pF)

3000

120kbps

20kbps

4000

5000

4000

5000

FIGURE 12. LOW SPEED SUPPLY CURRENT vs LOAD

FIGURE 13. HIGH SPEED SUPPLY CURRENT vs LO AD

CAPACITANCE WHEN TRANSMITTING DATA

10

CAPACITANCE WHEN TRANSMITTING DATA

ICL3237E

www.BDTIC.com/Intersil

Typical Performance Curves V

3.5

3.0

2.5

2.0

1.5

1.0

SUPPLY CURRENT (mA)

0.5

0

2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0

FIGURE 14. SUPPLY CURRENT vs SUPPLY VOLTAGE

Die Characteristics

SUBSTRATE POTENTIAL (POWERED UP):

GND

TRANSISTOR COUNT:

619

PROCES

Si Gate CMOS

= 3.3V, TA = 25oC (Continued)

CC

SUPPLY VOLTAGE (V)

NO LOAD
ALL OUTPUTS STATIC

11

ICL3237E

www.BDTIC.com/Intersil

Shrink Small Outline Plastic Packages (SSOP)

N

INDEX
AREA

123

-A­D

e

B

0.25(0.010) C AM BS

NOTES:

8. Symbols are defined in the “MO Series Symbol List” in Section 2.2
of Publication Number 95.

9. Dimensioning and tolerancing per ANSI Y14.5M-1982.

10. Dimension “D” does not include mold flash, protrusions or gate
burrs. Mold flash, protrusion and gate burrs shall not exceed

0.20mm (0.0078 inch) per side.

11. Dimension “E” does not include interlead flash or protrusions. In­terlead flash and protrusions shall not exceed 0.20mm (0.0078
inch) per side.

12. The chamfer on the body is optional. If it is not present, a visual
index feature must be located within the crosshatched area.

13. “L” is the length of terminal for soldering to a substrate.

14. “N” is the number of terminal positions.

15. Terminal numbers are shown for reference only.

16. Dimension “B” does not include dambar protrusion. Allowable
dambar protrusion shall be 0.13mm (0.005 inch) total in excess of
“B” dimension at maximum material condition.

17. Controlling dimension: MILLIMETER. Converted inch dimensions
are not necessarily exact.

E

-B-

SEATING PLANE

A

-C-

M

0.25(0.010) BM M

H

α

µ

A1

0.10(0.004)

GAUGE
PLANE

0.25

0.010

A2

L

C

M28.209 (JEDEC MO-150-AH ISSUE B)

28 LEAD SHRINK SMALL OUTLINE PLASTIC PACKAGE

INCHES MILLIMETERS

SYMBOL

A - 0.078 - 2.00 ­A1 0.002 - 0.05 - ­A2 0.065 0.072 1.65 1.85 -

B 0.009 0.014 0.22 0.38 9

C 0.004 0.009 0.09 0.25 -

D 0.390 0.413 9.90 10.50 3

E 0.197 0.220 5.00 5.60 4

e 0.026 BSC 0.65 BSC -

H 0.292 0.322 7.40 8.20 -

L 0.022 0.037 0.55 0.95 6

N28 287

o

α

0

o

8

o

0

o

8

Rev. 1 3/95

NOTESMIN MAX MIN MAX

-

All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems.

Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality

Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without
notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and
reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result
from its use. No license is granted b y implica tion or ot herw ise un der any patent or patent rights of Intersil or its subsidiaries.

For information regarding Intersil Corporation and its products, see www.intersil.com

12