MAX3230E_08 [MAXIM]
±15kV ESD-Protected +2.5V to +5.5V RS-232 Transceivers in UCSP and WLP; ± 15kV ESD保护， + 2.5V至+ 5.5V的RS - 232收发器， UCSP和WLP
| 型号： | MAX3230E_08 |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | ±15kV ESD-Protected +2.5V to +5.5V RS-232 Transceivers in UCSP and WLP |
| 文件： | 总16页 (文件大小：171K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-3250; Rev 1; 10/08
1ꢀ5k EꢁDꢂ-rotected +2.ꢀk to +ꢀ.ꢀk
Rꢁꢂ232 Transceivers in UCꢁ- and WL-
0/MX231AE
General Description
Features
♦ 6 x 5 Chip-Scale Package (UCSP) and WLP
The MAX3230E/AE and MAX3231E/AE are +2.5V to
+5.5V powered EIA/TIA-232 and V.28/V.24 communica-
tions interfaces with low power requirements, high data-
rate capabilities, and enhanced electrostatic discharge
(ESD) protection, in a chip-scale package (UCSP™)
and WLP package. All transmitter outputs and receiver
inputs are protected to 15kV using IEC 1000-4-2 Air-
Gap Discharge, 8kV using IEC 1000-4-2 Contact
Discharge, and 15kV using the ꢀuman ꢁodꢂ Model.
Package
♦ ESD Protection for RS-232 I/O Pins
±±5kꢀVIEC ±111-ꢁ-2 ꢂir-ꢃap Discharge
±ꢄkꢀVIEC ±111-ꢁ-2 Contact Discharge
±±5kꢀV—Huan ꢅodꢆ ꢇodel
♦ ±µꢂ Low-Power ꢂHtoShHtdown
♦ 251kbps ꢃHaranteed Data Rate
♦ ꢇeet EIꢂ/TIꢂ-232 Specifications Down to +3.±ꢀ
The MAX3230E/AE and MAX3231E/AE achieve a 1µA
supplꢂ current with Maxim’s AutoShutdown™ feature.
Theꢂ save power without changing the existing ꢁIOS or
operating sꢂstems bꢂ entering low-power shutdown
mode when the RS-232 cable is disconnected, or when
the transmitters of the connected peripherals are off.
♦ RS-232 Coupatible to +2.5ꢀ ꢂllows Operation
frou Single Li+ Cell
♦ Suall 1.±µF Capacitors
♦ ConfigHrable Logic Levels
Ordering Information
The transceivers have a proprietarꢂ low-dropout trans-
mitter output stage, delivering RS-232-compliant perfor-
mance from a +3.1V to +5.5V supplꢂ, and RS-232-
compatible performance with a supplꢂ voltage as low
as +2.5V. The dual charge pump requires onlꢂ four,
small 0.1µF capacitors for operation from a +3.0V sup-
plꢂ. Each device is guaranteed to run at data rates of
250kbps while maintaining RS-232 output levels.
PꢂRT
TEꢇP RꢂNꢃE ꢅUꢇP-PꢂCKꢂꢃE
-40°C to +85°C 6 x 5 UCSP
-40°C to +85°C 6 x 5 WLP
-40°C to +85°C 6 x 5 UCSP
-40°C to +85°C 6 x 5 WLP
ꢇꢂX3231EEꢁV-T
ꢇꢂX3231ꢂEEWV+-T
ꢇꢂX323±EEꢁV-T
ꢇꢂX323±ꢂEEWV+-T
+Denotes a lead-free/RoꢀS-compliant package.
T = Tape-and-reel.
The MAX3230E/AE and MAX3231E/AE offer a separate
power-supplꢂ input for the logic interface, allowing con-
figurable logic levels on the receiver outputs and trans-
Typical Operating Circuits
mitter inputs. Operating over a +1.65V to V
range, V
L
CC
2.5V TO 5.5V 1.65V TO 5.5V
provides the MAX3230E/AE and MAX3231E/AE com-
patibilitꢂ with multiple logic families.
0.1μF
The MAX3231E/AE contains one receiver and one trans-
mitter. The MAX3230E/AE contains two receivers and two
transmitters. The MAX3230E/AE and MAX3231E/AE are
available in tinꢂ chip-scale and WLP packaging and are
specified across the extended industrial (-40°C to +85°C)
temperature range.
C
BYPASS
0.1μF
A1
A5
V
V
C1
CC
B1
A4
L
C1+
V+
C3
0.1μF
C1
0.1μF
D1
A2
C1-
C2+
MAX3230E/AE
V-
C4
0.1μF
C2
0.1μF
A3
V
L
C2-
T1OUT
A6 T1IN
E3
Applications
RS-232
OUTPUTS
TTL/CMOS
INPUTS
V
L
B6
T2IN
T2OUT E4
Personal Digital Assistants
Cell-Phone Data Lump Cables
Set-Top ꢁoxes
V
L
R1IN
D6 R1OUT
E6
5kΩ
TTL/CMOS
OUTPUTS
RS-232
INPUTS
V
L
ꢀandheld Devices
C6
R2OUT
R2IN E5
5kΩ
Cell Phones
Tꢆpical Operating CircHits continHed at end of data sheet.
Pin ConfigHrations appear at end of data sheet.
TO POWER-
MANAGEMENT
UNIT
E2
INVALID
FORCEON
FORCEOFF C5
B5
V
L
UCSP is a trademark of Maxim Integrated Products, Inc.
GND
E1
AutoShutdown is a trademark of Maxim Integrated Products, Inc.
________________________________________________________________ ꢇaxiu Integrated ProdHcts
±
For pricing, deliverꢆ, and ordering inforuation, please contact ꢇaxiu Direct at ±-ꢄꢄꢄ-629-ꢁ6ꢁ2,
or visit ꢇaxiu’s website at www.uaxiu-ic.cou.
1ꢀ5k EꢁDꢂ-rotected +2.ꢀk to +ꢀ.ꢀk
Rꢁꢂ232 Transceivers in UCꢁ- and WL-
ꢂꢅSOLUTE ꢇꢂXIꢇUꢇ RꢂTINꢃS
CC
V
to GND...........................................................-0.3V to +6.0V
Short-Circuit Duration T OUT to GND........................Continuous
_
V+ to GND.............................................................-0.3V to +7.0V
V- to GND ..............................................................+0.3V to -7.0V
V+ to |V-| (Note 1) ................................................................+13V
Continuous Power Dissipation (T = +70°C)
A
6 ✕ 5 UCSP (derate 10.1mW/°C above +70°C) ...........805mW
6 ✕ 5 WLP (derate 20mW/°C above +70°C).....................1.6W
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range.............................-65°C to +150°C
ꢁump Temperature (soldering)
V to GND..............................................................-0.3V to +6.0V
L
Input Voltages
T_IN_, FORCEON, FORCEOFF to GND.....-0.3V to (V + 0.3V)
L
R_IN_ to GND ................................................................... 25V
Output Voltages
T_OUT to GND............................................................... 13.2V
Infrared (15s) ...............................................................+200°C
Vapor Phase (20s) .......................................................+215°C
R_OUT INVALID to GND ............................-0.3V to (V + 0.3V)
L
CC
INVALID to GND.........................................-0.3V to (V
+ 0.3V)
Note ±: V+ and V- can have maximum magnitudes of 7V, but their absolute difference cannot exceed 13V.
Stresses beꢂond those listed under “Absolute Maximum Ratings” maꢂ cause permanent damage to the device. These are stress ratings onlꢂ, and functional
operation of the device at these or anꢂ other conditions beꢂond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods maꢂ affect device reliabilitꢂ.
ELECTRICꢂL C—ꢂRꢂCTERISTICS
(V
= +2.5V to +5.5V, V = +1.65V to +5.5V, C1–C4 = 0.1µF, tested at +3.3V 10ꢃ, T = T
to T
. Tꢂpical values are at T =
MAX A
CC
L
A
MIN
+25°C, unless otherwise noted.) (Note 2)
PꢂRꢂꢇETER
SYꢇꢅOL
CONDITIONS
ꢇIN
TYP
ꢇꢂX
UNITS
DC C—ꢂRꢂCTERISTICS
V Input Voltage Range
V
1.65
V
CC
+ 0.3
10
V
L
L
FORCEON = GND
FORCEOFF = V , all R open
µA
L
IN
V
Supplꢂ Current,
CC
I
CC
AutoShutdown
FORCEOFF = GND
10
1
FORCEON, FORCEOFF = V
mA
mA
L
V
Supplꢂ Current,
CC
I
FORCEON = FORCEOFF = V , no load
0.3
1
1
CC
L
AutoShutdown Disabled
FORCEON or FORCEOFF = GND or V ,
L
V Supplꢂ Current
L
T_IN, I
µA
L
V
= V = +5V, no receivers switching
L
CC
LOꢃIC INPUTS
Input-Logic Low
T_IN, FORCEON, FORCEOFF
T_IN, FORCEON, FORCEOFF
0.4
1
V
V
✕
Input-Logic ꢀigh
0.66
V
L
Transmitter Input ꢀꢂsteresis
Input Leakage Current
RECEIꢀER OUTPUTS
0.5
V
T_IN, FORCEON, FORCEOFF
0.01
µA
0/MX231AE
R_OUT, receivers disabled, FORCEOFF =
GND or in AutoShutdown
Output Leakage Currents
10
µA
Output-Voltage Low
Output-Voltage ꢀigh
I
I
= 0.8mA
= -0.5mA
0.4
V
V
OUT
V - 0.4 V - 0.1
OUT
L
L
2
_______________________________________________________________________________________
1ꢀ5k EꢁDꢂ-rotected +2.ꢀk to +ꢀ.ꢀk
Rꢁꢂ232 Transceivers in UCꢁ- and WL-
0/MX231AE
ELECTRICꢂL C—ꢂRꢂCTERISTICS (continHed)
(V
= +2.5V to +5.5V, V = +1.65V to +5.5V, C1–C4 = 0.1µF, tested at +3.3V 10ꢃ, T = T
to T
. Tꢂpical values are at T =
MAX A
CC
L
A
MIN
+25°C, unless otherwise noted.) (Note 2)
PꢂRꢂꢇETER
RECEIꢀER INPUTS
Input Voltage Range
SYꢇꢅOL
CONDITIONS
ꢇIN
TYP
ꢇꢂX
UNITS
-25
0.6
0.8
+25
V
V
V
V
V
V
= +3.3V
= +5.0V
= +3.3V
= +5.0V
1.2
1.7
1.3
1.8
0.5
5
CC
CC
CC
CC
Input-Threshold Low
Input-Threshold ꢀigh
T
T
= +25°C
= +25°C
A
2.4
2.4
V
A
Input ꢀꢂsteresis
V
Input Resistance
3
7
kΩ
ꢂUTOꢇꢂTIC S—UTDOWN
Positive threshold
Negative threshold
2.7
Receiver Input Threshold to
INVALID Output ꢀigh
Figure 3a
V
-2.7
-0.3
Receiver Input Threshold to
INVALID Output Low
+0.3
V
Receiver Positive or Negative
Threshold to INVALID ꢀigh
t
V
V
V
= +5.0V, Figure 3b
= +5.0V, Figure 3b
= +5.0V, Figure 3b
1
µs
µs
µs
INVꢀ
CC
CC
CC
Receiver Positive or Negative
Threshold to INVALID Low
t
30
INVL
Receiver Edge to Transmitters
Enabled
t
100
WU
INꢀꢂLID OUTPUT
Output-Voltage Low
Output-Voltage ꢀigh
TRꢂNSꢇITTER OUTPUTS
I
I
= 0.8mA
= -0.5mA
0.4
- 0.1
V
V
OUT
V
- 0.4
V
CC
OUT
CC
V
(V
Mode Switch Point
Falling)
CC
T_OUT = 5.0V to 3.7V
T_OUT = 3.7V to 5.0V
2.85
3.3
3.10
3.7
V
CC
V
(V
Mode Switch Point
Rising)
CC
V
CC
V
Mode Switch-Point ꢀꢂsteresis
400
5.4
mV
CC
V
V
= +3.1V to +5.5V,
falling, T = +25°C
A
CC
CC
All transmitter
outputs loaded
with 3kΩ to
ground
5
Output Voltage Swing
V
V
V
= +2.5V to +3.1V,
rising
CC
CC
3.7
Output Resistance
V
= V+ = V- = 0, T_OUT = 2V
300
10M
Ω
CC
Output Short-Circuit Current
Output Leakage Current
ESD PROTECTION
60
25
mA
µA
T_OUT = 12V, transmitters disabled
ꢀuman ꢁodꢂ Model
15
15
8
R_IN, T_OUT
kV
IEC 1000-4-2 Air-Gap Discharge
IEC 1000-4-2 Contact Discharge
_______________________________________________________________________________________
3
1ꢀ5k EꢁDꢂ-rotected +2.ꢀk to +ꢀ.ꢀk
Rꢁꢂ232 Transceivers in UCꢁ- and WL-
TIꢇINꢃ C—ꢂRꢂCTERISTICS
(V
= +2.5V to +5.5V, V = +1.65V to +5.5V, C1–C4 = 0.1µF, tested at +3.3V 10ꢃ, T = T
to T
. Tꢂpical values are at T =
MAX A
CC
L
A
MIN
+25°C, unless otherwise noted.) (Note 2)
PꢂRꢂꢇETER
SYꢇꢅOL
CONDITIONS
ꢇIN
TYP
ꢇꢂX
UNITS
R = 3kΩ, C = 1000pF, one transmitter
switching
L
L
Maximum Data Rate
250
kbps
µs
Receiver input to receiver output,
C = 150pF
Receiver Propagation Delaꢂ
0.15
L
Receiver-Output Enable Time
Receiver-Output Disable Time
Transmitter Skew
V
V
= V = +5V
200
200
100
50
ns
ns
ns
ns
CC
CC
L
= V = +5V
L
| t
| t
- t
|
|
PꢀL PLꢀ
Receiver Skew
- t
PꢀL PLꢀ
R = 3kΩ to 7kΩ, C = 150pF to
L
L
Transition-Region Slew Rate
6
30
V/µs
1000pF, T = +25°C
A
Note 2: V
must be greater than V .
L
CC
Typical Operating Characteristics
(V
CC
= +3.3V, 250kbps data rate, 0.1µF capacitors, all transmitters loaded with 3kΩ and C , T = +25°C, unless otherwise noted.)
L
A
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
OPERATING SUPPLY CURRENT
vs. LOAD CAPACITANCE (MAX3231E)
SLEW RATE vs. LOAD CAPACITANCE
20
18
16
14
12
10
8
6
30
25
20
15
10
5
V
CC
RISING
4
2
V
OH
250kbps
V
CC
= 5.5V
0
V
OL
-2
-4
-6
6
4
V
CC
= 2.5V
2
20kbps
0
0
0
500 1000 1500 2000 2500 3000
LOAD CAPACITANCE (pF)
0
500 1000 1500 2000 2500 3000
LOAD CAPACITANCE (pF)
0
500 1000 1500 2000 2500 3000
LOAD CAPACITANCE (pF)
0/MX231AE
ꢁ
_______________________________________________________________________________________
1ꢀ5k EꢁDꢂ-rotected +2.ꢀk to +ꢀ.ꢀk
Rꢁꢂ232 Transceivers in UCꢁ- and WL-
0/MX231AE
Typical Operating Characteristics (continued)
(V
CC
= +3.3V, 250kbps data rate, 0.1µF capacitors, all transmitters loaded with 3kΩ and C , T = +25°C, unless otherwise noted.)
L
A
OPERATING SUPPLY CURRENT
vs. SUPPLY VOLTAGE (MAX3231E)
TRANSMITTER OUTPUT VOLTAGE
vs. SUPPLY VOLTAGE (V RISING)
TRANSMITTER OUTPUT VOLTAGE
vs. SUPPLY VOLTAGE (V FALLING)
CC
CC
20
10
8
10
8
18
16
14
12
10
8
6
6
4
4
V
OH
V
OH
2
2
0
0
-2
-4
-6
-8
-2
-4
-6
-8
V
OL
V
OL
6
4
2
0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
2.5
3.0
3.5
4.0
4.5
5.0
5.5
2.5
3.0
3.5
4.0
4.5
5.0
5.5
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
-in Description
ꢅUꢇP
NꢂꢇE
FUNCTION
ꢇꢂX3231E/ ꢇꢂX323±E/
ꢇꢂX3231ꢂE ꢇꢂX323±ꢂE
A1
A2
A3
A4
A1
A2
A3
A4
V
Supplꢂ Voltage. +2.5V to +5.5V supplꢂ voltage.
CC
C2+
C2-
V-
Inverting Charge-Pump Capacitor Positive Terminal
Inverting Charge-Pump Capacitor Negative Terminal
Negative Charge-Pump Output. -5.5V/-4.0V generated bꢂ charge pump.
Logic Voltage Input. Logic-level input for receiver outputs and transmitter inputs.
A5
A5
A6
V
L
Connect V to the sꢂstem-logic supplꢂ voltage or V
L
if no logic supplꢂ is required.
CC
A6, ꢁ6
T_IN
V+
Transmitter Input(s)
Positive Charge-Pump Output. +5.5V/+4.0V generated bꢂ charge pump. If charge
pump is generating +4.0V, the device has switched from RS-232-compliant to RS-232-
compatible mode.
ꢁ1
ꢁ1
ꢁ2, ꢁ3, ꢁ4,
C2, C3, C4,
D2–D5
ꢁ2, ꢁ3, ꢁ4,
C2, C3, C4,
D2–D5
No Connection. The MAX3230E/MAX3231E are not populated with solder bumps at
these locations. The MAX3230AE/MAX3231AE are populated with electricallꢂ isolated
solder bumps at these locations.
N.C.
Active ꢀigh FORCEON Input. Drive FORCEON high to override automatic circuitrꢂ,
keeping transmitters and charge pumps on.
ꢁ5
C1
ꢁ5
C1
FORCEON
C1+
Positive Regulated Charge-Pump Capacitor Positive Terminal
Active-Low FORCEOFF Input. Drive FORCEOFF low to shut down transmitters,
C5
C5
FORCEOFF receivers, and on-board charge pump. This overrides all automatic circuitrꢂ and
FORCEON.
_______________________________________________________________________________________
5
1ꢀ5k EꢁDꢂ-rotected +2.ꢀk to +ꢀ.ꢀk
Rꢁꢂ232 Transceivers in UCꢁ- and WL-
-in Description (continued)
ꢅUꢇP
NꢂꢇE
FUNCTION
ꢇꢂX3231E/ ꢇꢂX323±E/
ꢇꢂX3231ꢂE ꢇꢂX323±ꢂE
C6, D6
D1
C6
D1
E1
R_OUT
C1-
Receiver Output(s)
Positive Regulated Charge-Pump Capacitor Negative Terminal
Ground
E1
GND
Valid Signal-Detector Output. Output INVALID is enabled low if no valid RS-232 level is
present on anꢂ receiver input.
E2
E2
INVALID
E3, E4
E5, E6
E3
E5
T_OUT
R_IN
RS-232 Transmitter Output(s)
RS-232 Receiver Input(s)
ꢁ6, D6, E4,
E6
No Connection. These locations are populated with solder bumps, but are electricallꢂ
isolated.
—
N.C.
in regulation until the batterꢂ voltage drops below +3.1V.
The output regulation points then change to 4.0V.
Detailed Description
Dual Mode™ Regulated Chargeꢂ-ump
koltage Converter
When V
is rising, the charge pump generates an out-
CC
put voltage of 4.0V, while V
is between +2.5V and
CC
The MAX3230E/AE and MAX3231E/AE internal power
supplꢂ consists of a dual-mode regulated charge
pump. For supplꢂ voltages above +3.7V, the charge
pump generates +5.5V at V+ and -5.5V at V-. The
charge pumps operate in a discontinuous mode. If the
output voltages are less than 5.5V, the charge pumps
are enabled. If the output voltages exceed 5.5V, the
charge pumps are disabled.
+3.5V. When V
+3.5V, the charge pump switches modes to generate
an output of 5.5V.
rises above the switchover voltage of
CC
Table 1 shows different supplꢂ schemes and their oper-
ating voltage ranges.
Rꢁꢂ232 Transmitters
The transmitters are inverting level translators that
convert CMOS logic levels to RS-232 levels. The
MAX3230E/AE and MAX3231E/AE automaticallꢂ reduce
the RS-232-compliant levels ( 5.5V) to RS-232-compat-
For supplꢂ voltages below +2.85V, the charge pump
generates +4.0V at V+ and -4.0V at V-. The charge
pumps operate in a discontinuous mode. If the output
voltages are less than 4.0V, the charge pumps are
enabled. If the output voltages exceed 4.0V, the
charge pumps are disabled.
ible levels ( 4.0V) when V
falls below approximatelꢂ
CC
+3.1V. The reduced levels also reduce supplꢂ-current
requirements, extending batterꢂ life. ꢁuilt-in hꢂsteresis
of approximatelꢂ 400mV for V
ensures that the RS-
CC
Each charge pump requires a flꢂing capacitor (C1, C2)
and a reservoir capacitor (C3, C4) to generate the V+
and V- supplꢂ voltages.
koltage Generation in the
ꢁwitchover Region
V
CC
4V
The MAX3230E/AE and MAX3231E/AE include a
switchover circuit between these two modes that have
approximatelꢂ 400mV of hꢂsteresis around the
switchover point. The hꢂsteresis is shown in Figure 1.
This large hꢂsteresis eliminates mode changes due to
power-supplꢂ bounce.
0
0/MX231AE
V+
6V
For example, a three-cell NiMh batterꢂ sꢂstem starts at
V
= +3.6V, and the charge pump generates an out-
CC
0
put voltage of 5.5V. As the batterꢂ discharges, the
MAX3230E/AE and MAX3231E/AE maintain the outputs
20ms/div
Figure 1. V+ Switchover for Changing V
Dual Mode is a trademark of Maxim Integrated Products, Inc.
CC
6
_______________________________________________________________________________________
1ꢀ5k EꢁDꢂ-rotected +2.ꢀk to +ꢀ.ꢀk
Rꢁꢂ232 Transceivers in UCꢁ- and WL-
0/MX231AE
Table ±. Operating SHpplꢆ Options
SYSTEꢇ SUPPLY (ꢀ)
1 Li+ Cell
ꢀ
(ꢀ)
ꢀ (ꢀ)
L
RS-232 ꢇODE
CC
+2.4 to +4.2
+2.4 to +3.8
Regulated sꢂstem voltage
Regulated sꢂstem voltage
Compliant/Compatible
Compliant/Compatible
3 NiCad/NiMh Cells
Regulated Voltage Onlꢂ
+3.0 to +5.5
+2.5 to +3.0
+3.0 to +5.5
+2.5 to +3.0
Compliant
(V
CC
falling)
Regulated Voltage Onlꢂ
(V falling)
Compatible
CC
Table 2. OHtpHt Control TrHth Table
TRꢂNSCEIꢀER STꢂTUS
Shutdown (AutoShutdown)
Shutdown (Forced Off)
FORCEON
Low
FORCEOFF
ꢀigh
RECEIꢀER STꢂTUS
ꢀigh impedance
INVALID
Low
†
X
Low
ꢀigh impedance
Active
Normal Operation (Forced On)
Normal Operation (AutoShutdown)
ꢀigh
Low
ꢀigh
†
ꢀigh
Active
ꢀigh
X = Don’t care.
† = INVALID output state is determined bꢂ R_IN input levels.
232 output levels do not change if V
is noisꢂ or has a
signal levels have been detected on anꢂ receiver inputs.
CC
sudden current draw causing the supplꢂ voltage to drop
slightlꢂ. The outputs return to RS-232-compliant levels
INVALID is functional in anꢂ mode (Figures 2 and 3).
Autoꢁhutdown
The MAX3230E/AE and MAX3231E/AE achieve a 1µA
supplꢂ current with Maxim’s AutoShutdown feature,
which operates when FORCEON is low and FORCEOFF
is high. When these devices sense no valid signal lev-
els on all receiver inputs for 30µs, the on-board charge
( 5.5V) when V
rises above approximatelꢂ +3.5V.
CC
The MAX3230E/AE and MAX3231E/AE transmitters
guarantee a 250kbps data rate with worst-case loads of
3kΩ in parallel with 1000pF.
When FORCEOFF is driven to ground, the transmitters
and receivers are disabled and the outputs become
high impedance. When the AutoShutdown circuitrꢂ
senses that all receiver and transmitter inputs are inac-
tive for more than 30µs, the transmitters are disabled
and the outputs go to a high-impedance state. When
the power is off, the MAX3230E/AE and MAX3231E/AE
permit the transmitter outputs to be driven up to 12V.
pump and drivers are shut off, reducing V
supplꢂ
CC
current to 1µA. This occurs if the RS-232 cable is dis-
connected or the connected peripheral transmitters are
turned off. The device turns on again when a valid level
is applied to anꢂ RS-232 receiver input. As a result, the
sꢂstem saves power without changes to the existing
ꢁIOS or operating sꢂstem.
The transmitter inputs do not have pullup resistors.
Table 2 and Figure 2c summarize the MAX3230E/AE
and MAX3231E/AE operating modes. FORCEON and
FORCEOFF override AutoShutdown. When neither con-
trol is asserted, the IC selects between these states
automaticallꢂ, based on receiver input levels. Figures
2a, 2b, and 3a depict valid and invalid RS-232-receiver
levels. Figures 3a and 3b show the input levels and tim-
ing diagram for AutoShutdown operation.
Connect unused inputs to GND or V .
L
Rꢁꢂ232 Receivers
The MAX3230E/AE and MAX3231E/AE receivers con-
vert RS-232 signals to logic-output levels. All receivers
have inverting tri-state outputs and can be active or
inactive. In shutdown (FORCEOFF = low) or in
AutoShutdown, the MAX3230E/AE and MAX3231E/AE
receivers are in a high-impedance state (Table 2).
A sꢂstem with AutoShutdown can require time to wake
up. Figure 4 shows a circuit that forces the transmitters
on for 100ms, allowing enough time for the other
sꢂstem to realize that the MAX3230E/AE and
The MAX3230E/AE and MAX3231E/AE feature an
INVALID output that is enabled low when no valid RS-232
_______________________________________________________________________________________
7
1ꢀ5k EꢁDꢂ-rotected +2.ꢀk to +ꢀ.ꢀk
Rꢁꢂ232 Transceivers in UCꢁ- and WL-
FORCEOFF
+0.3V
POWER DOWN
TO MAX323 _E
POWER SUPPLY
AND TRANSMITTERS
V
CC
R_IN
-0.3V
30μs
COUNTER
R
INVALID
FORCEON
INVALID
TRANSMITTERS ARE DISABLED, REDUCING SUPPLY CURRENT TO 1μA IF
ALL RECEIVER INPUTS ARE BETWEEN +0.3V AND -0.3V FOR AT LEAST 30μs.
INVALID IS AN INTERNALLY GENERATED SIGNAL
THAT IS USED BY THE AutoShutdown LOGIC
AND APPEARS AS AN OUTPUT OF THE DEVICE.
Figure 2a. MAX323_E Entering 1µA Supplꢂ Mode with
AutoShutdown
POWER DOWN IS ONLY AN INTERNAL SIGNAL.
IT CONTROLS THE OPERATIONAL STATUS OF
THE TRANSMITTERS AND THE POWER SUPPLIES.
+2.7V
Figure 2c. MAX323_E AutoShutdown Logic
microcontroller (µC) then drives FORCEOFF and
FORCEON like a SHDN input. INVALID can be used to
alert the µC to indicate serial data activitꢂ.
TO MAX323 _E
POWER SUPPLY
R_IN
30μs
COUNTER
R
INVALID
-2.7V
1ꢀ5k EꢁD -rotection
As with all Maxim devices, ESD-protection structures
are incorporated on all pins to protect against electro-
static discharges encountered during handling and
assemblꢂ. The driver outputs and receiver inputs of the
MAX3230E/AE and MAX3231E/AE have extra protec-
tion against static electricitꢂ. Maxim’s engineers have
developed state-of-the-art structures to protect these
pins against ESD of 15kV without damage. The ESD
structures withstand high ESD in all states: normal
operation, shutdown, and power-down. After an ESD
event, Maxim’s E-versions keep working without
latchup, whereas competing RS-232 products can latch
and must be powered down to remove latchup.
TRANSMITTERS ARE ENABLED IF:
ANY RECEIVER INPUT IS GREATER THAN +2.7V OR LESS THAN -2.7V.
ANY RECEIVER INPUT HAS BEEN BETWEEN +0.3V AND -0.3V FOR LESS THAN 30μs.
Figure 2b. MAX323_E with Transmitters Enabled Using
AutoShutdown
MAX3231E/AE are active. If the other sꢂstem transmits
valid RS-232 signals within that time, the RS-232 ports
on both sꢂstems remain enabled.
When shut down, the device’s charge pumps are off,
V+ is pulled to V , V- is pulled to ground, and the
CC
transmitter outputs are high impedance. The time
required to exit shutdown is tꢂpicallꢂ 100µs (Figure 3b).
ESD protection can be tested in various waꢂs; the trans-
mitter outputs and receiver inputs of this product familꢂ
are characterized for protection to the following limits:
k Logic ꢁupply Input
L
Unlike other RS-232 interface devices, where the receiv-
1) 15kV using the ꢀuman ꢁodꢂ Model
er outputs swing between 0 and V , the MAX3230E/AE
CC
and MAX3231E/AE feature a separate logic supplꢂ input
2) 8kV using the Contact Discharge method specified
in IEC 1000-4-2
(V ) that sets V
for the receiver outputs. The transmit-
L
Oꢀ
ter inputs (T_IN), FORCEON, and FORCEOFF, are also
3) 15kV using the IEC 1000-4-2 Air-Gap method
referred to V . This feature allows maximum flexibilitꢂ in
L
interfacing to different sꢂstems and logic levels.
ESD Test Conditions
ESD performance depends on a varietꢂ of conditions.
Contact Maxim for a reliabilitꢂ report that documents test
setup, test methodologꢂ, and test results.
Connect V to the sꢂstem’s logic supplꢂ voltage (+1.65V
L
1
to +5.5V), and bꢂpass it with a 0.1µF capacitor to GND.
If the logic supplꢂ is the same as V , connect V to
CC
L
V
V
. Alwaꢂs enable V
before enabling the V supplꢂ.
CC
CC
CC L
must be greater than or equal to the V supplꢂ.
L
—Huan ꢅodꢆ ꢇodel
Figure 5a shows the ꢀuman ꢁodꢂ Model. Figure 5b
shows the current waveform it generates when dis-
charged into a low impedance. This model consists of a
100pF capacitor charged to the ESD voltage of interest,
ꢁoftwareꢂControlled ꢁhutdown
If direct software control is desired, connect FORCEOFF
and FORCEON together to disable AutoShutdown. The
ꢄ
_______________________________________________________________________________________
1ꢀ5k EꢁDꢂ-rotected +2.ꢀk to +ꢀ.ꢀk
Rꢁꢂ232 Transceivers in UCꢁ- and WL-
0/MX231AE
which is then discharged into the test device through a
1.5kΩ resistor.
TRANSMITTERS ENABLED, INVALID HIGH
IEC ±111-ꢁ-2
+2.7V
The IEC 1000-4-2 standard covers ESD testing and per-
INDETERMINATE
formance of finished equipment. It does not specificallꢂ
+0.3V
0
refer to ICs. The MAX3230E/AE and MAX3231E/AE aid
AutoShutdown, TRANSMITTERS DISABLED,
1μA SUPPLY CURRENT, INVALID LOW
in designing equipment that meets Level 4 (the highest
-0.3V
level) of IEC 1000-4-2, without the need for additional
ESD-protection components.
INDETERMINATE
-2.7V
The major difference between tests done using the
ꢀuman ꢁodꢂ Model and IEC 1000-4-2 is a higher peak
TRANSMITTERS ENABLED, INVALID HIGH
current in IEC 1000-4-2, because series resistance is
lower in the IEC 1000-4-2 model. ꢀence, the ESD with-
stands voltage measured to IEC 1000-4-2 and is gener-
allꢂ lower than that measured using the ꢀuman ꢁodꢂ
Model. Figure 6a shows the IEC 1000-4-2 model, and
Figure 6b shows the current waveform for the 8kV IEC
a)
RECEIVER
INPUT
VOLTAGE
(V)
INVALID
REGION
1000-4-2 Level 4 ESD Contact Discharge test.
The Air-Gap test involves approaching the device with a
charged probe. The Contact Discharge method connects
the probe to the device before the probe is energized.
V
CC
0
INVALID
OUTPUT
(V)
ꢇachine ꢇodel
The Machine Model for ESD tests all pins using a 200pF
storage capacitor and zero discharge resistance. Its
t
t
INVH
INVL
objective is to emulate the stress caused bꢂ contact that
occurs with handling and assemblꢂ during manufactur-
ing. Of course, all pins require this protection during
manufacturing, not just RS-232 inputs and outputs.
Therefore, after PC board assemblꢂ, the Machine Model
is less relevant to I/O ports.
t
WU
V+
V
CC
0
V-
Applications Information
b)
Capacitor ꢁelection
The capacitor tꢂpe used for C1–C4 is not critical for
proper operation; either polarized or nonpolarized
capacitors can be used. ꢀowever, ceramic chip capaci-
tors with an X7R or X5R dielectric work best. The charge
pump requires 0.1µF capacitors for 3.3V operation. For
other supplꢂ voltages, see Table 3 for required capaci-
tor values. Do not use values smaller than those listed in
Table 3. Increasing the capacitor values (e.g., bꢂ a fac-
tor of 2) reduces ripple on the transmitter outputs and
slightlꢂ reduces power consumption. C2, C3, and C4
can be increased without changing the vaue of C1.
Figure 3. AutoShutdown Trip Levels
POWER-
MANAGEMENT
UNIT
MASTER SHDN LINE
0.1μF
1MΩ
FORCEOFF FORCEON
MAX3230E/AE
MAX3231E/AE
CaHtion: Do not increase C1 without also increasing
the values of C2, C3, and C4 to maintain the proper
ratios (C1 to the other capacitors).
Figure 4. AutoShutdown with Initial Turn-On to Wake Up a
Mouse or Another Sꢂstem
When using the minimum required capacitor values,
make sure the capacitor value does not degrade exces-
sivelꢂ with temperature. If in doubt, use capacitors with
_______________________________________________________________________________________
9
1ꢀ5k EꢁDꢂ-rotected +2.ꢀk to +ꢀ.ꢀk
Rꢁꢂ232 Transceivers in UCꢁ- and WL-
I
R
C
1MΩ
R 1500Ω
D
100%
DISCHARGE
RESISTANCE
CHARGE-CURRENT-
LIMIT RESISTOR
90%
HIGH-
VOLTAGE
DC
DEVICE
UNDER
TEST
C
100pF
STORAGE
CAPACITOR
s
SOURCE
10%
Figure 5a. ꢀuman ꢁodꢂ ESD Test Models
t
= 0.7ns to 1ns
r
t
30ns
60ns
I
P
100%
90%
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
Figure 6b. IEC 1000-4-2 ESD Generator Current Waveform
I
r
AMPERES
Table 3. ReqHired Capacitor ꢀalHes
36.8%
ꢀ
(ꢀ)
C±, C
(µF)
C2, C3, Cꢁ (µF)
CC
ꢅYPꢂSS
0.22
2.5 to 3.0
3.0 to 3.6
4.5 to 5.5
3.0 to 5.5
0.22
0.1
0.33
1
10%
0
0.1
TIME
0
t
RL
0.047
0.22
t
DL
CURRENT WAVEFORM
Figure 5b. ꢀuman ꢁodꢂ Model Current Waveform
supplꢂ noise, use a capacitor of the same value as the
charge-pump capacitor C1. Connect bꢂpass capaci-
tors as close to the IC as possible.
R
C
50MΩ TO 100MΩ
R 330Ω
D
Transmitter Outputs when
Exiting ꢁhutdown
DISCHARGE
RESISTANCE
CHARGE-CURRENT-
LIMIT RESISTOR
Figure 7 shows a transmitter output when exiting shut-
down mode. The transmitter is loaded with 3kΩ in par-
allel with 1000pF. The transmitter output displaꢂs no
ringing or undesirable transients as it comes out of
shutdown, and is enabled onlꢂ when the magnitude of
V- exceeds approximatelꢂ -3V.
HIGH-
VOLTAGE
DC
DEVICE
UNDER
TEST
C
s
150pF
STORAGE
CAPACITOR
SOURCE
High Data Rates
The MAX3230E/AE and MAX3231E/AE maintain the
RS-232 5.0V minimum transmitter output voltage even
at high data rates. Figure 8 shows a transmitter loop-
back test circuit. Figure 9 shows a loopback test result
at 120kbps, and Figure 10 shows the same test at
250kbps. For Figure 9, the transmitter was driven at
120kbps into an RS-232 load in parallel with 1000pF.
For Figure 10, a single transmitter was driven at
250kbps and loaded with an RS-232 receiver in paral-
lel with 1000pF.
Figure 6a. IEC 1000-4-2 ESD Test Model
0/MX231AE
a larger nominal value. The capacitor’s equivalent series
resistance (ESR) usuallꢂ rises at low temperatures and
influences the amount of ripple on V+ and V-.
-owerꢂꢁupply Decoupling
In most circumstances, a 0.1µF V
bꢂpass capacitor
CC
is adequate. In applications that are sensitive to power-
±1 ______________________________________________________________________________________
1ꢀ5k EꢁDꢂ-rotected +2.ꢀk to +ꢀ.ꢀk
Rꢁꢂ232 Transceivers in UCꢁ- and WL-
0/MX231AE
5V
5V/div
T_IN
FORCEON =
FORCEOFF
0
0
5V
T_OUT
R_OUT
0
-5V
5V
0
2V/div
0
T_OUT
4μs/div
4μs/div
Figure 7. Transmitter Outputs Exiting Shutdown or Powering Up
Figure 9. Loopback Test Result at 120kbps
V
V
L
CC
CC
5V
0.1μF
C3
0.1μF
C1
T_IN
0
V
V
L
C1+
V+
V-
5V
C1-
C2+
T_OUT
MAX3231E/AE
0
C2
C4
-5V
5V
0
C2-
V
V
L
L
T1IN
T1OUT
R_OUT
1000pF
R1IN
R1OUT
4μs/div
5kΩ
Figure 10. Loopback Test Result at 250kbps
TO POWER-
MANAGEMENT UNIT
INVALID
FORCEON
FORCEOFF
V
L
GND
Figure 8. Transmitter Loopback Test Circuit
UCꢁ- Applications Information
Chip Information
For the latest application details on UCSP construction,
dimensions, tape carrier information, PC board tech-
niques, bump-pad laꢂout, and recommended reflow
temperature profile, as well as the latest information on
reliabilitꢂ testing results, refer to the Application Note
UCSP—A Wafer-Level Chip-Scale Package available
on Maxim’s website at www.uaxiu-ic.cou/Hcsp.
TRANSISTOR COUNT: 698
PROCESS: CMOS
______________________________________________________________________________________ ±±
1ꢀ5k EꢁDꢂ-rotected +2.ꢀk to +ꢀ.ꢀk
Rꢁꢂ232 Transceivers in UCꢁ- and WL-
Typical Operating Circuits
(continued)
2.5V TO 5.5V 1.65V TO 5.5V
C
0.1μF
BYPASS
0.1μF
A1
A5
V
V
C1
CC
B1
A4
L
C1+
V+
C3
C1
0.1μF
0.1μF
D1
A2
C1-
C2+
MAX3231E/AE
V-
C4
C2
0.1μF
0.1μF
A3
A6
V
L
C2-
T1OUT
T1IN
E3
E5
V
L
RS-232
TTL/CMOS
R1IN
C6 R1OUT
5kΩ
TO POWER-
MANAGEMENT
UNIT
E2
INVALID
FORCEON
FORCEOFF C5
B5
V
L
GND
E1
0/MX231AE
±2 ______________________________________________________________________________________
1ꢀ5k EꢁDꢂ-rotected +2.ꢀk to +ꢀ.ꢀk
Rꢁꢂ232 Transceivers in UCꢁ- and WL-
0/MX231AE
-in Configurations
TOP VIEW
C2+
N.C.
N.C.
N.C.
C2-
N.C.
N.C.
N.C.
A
V
V-
V
T1IN
CC
L
V+
B
N.C.
N.C.
FON
T2IN
C
FOFF
R2OUT
C1+
C1-
N.C.
D
E
N.C.
R1OUT
INV
2
R2IN
5
R1IN
6
GND
1
T1OUT
3
T2OUT
4
FON = FORCEON
FOFF = FORCEOFF
INV = INVALID
MAX3230E/AE
______________________________________________________________________________________ ±3
1ꢀ5k EꢁDꢂ-rotected +2.ꢀk to +ꢀ.ꢀk
Rꢁꢂ232 Transceivers in UCꢁ- and WL-
-in Configurations (continued)
TOP VIEW
C2+
N.C.
N.C.
N.C.
C2-
N.C.
N.C.
N.C.
A
V
V-
V
T1IN
CC
L
V+
B
N.C.
N.C.
FON
N.C.
C
FOFF
R1OUT
C1+
C1-
N.C.
D
E
N.C.
N.C.
INV
2
R1IN
5
N.C.
6
GND
1
T1OUT
3
N.C.
4
FON = FORCEON
FOFF = FORCEOFF
INV = INVALID
MAX3231E/AE
0/MX231AE
±ꢁ ______________________________________________________________________________________
1ꢀ5k EꢁDꢂ-rotected +2.ꢀk to +ꢀ.ꢀk
Rꢁꢂ232 Transceivers in UCꢁ- and WL-
0/MX231AE
-ac5age Information
For the latest package outline information and land patterns, go to www.uaxiu-ic.cou/packages.
PꢂCKꢂꢃE TYPE
6 x 5 UCSP
PꢂCKꢂꢃE CODE
ꢁ30-2
DOCUꢇENT NO.
2±-1±23
6 x 5 WLP
W302A3-2
2±-11±6
______________________________________________________________________________________ ±5
1ꢀ5k EꢁDꢂ-rotected +2.ꢀk to +ꢀ.ꢀk
Rꢁꢂ232 Transceivers in UCꢁ- and WL-
Revision History
REꢀISION
NUꢇꢅER
REꢀISION
DꢂTE
PꢂꢃES
C—ꢂNꢃED
DESCRIPTION
0
1
5/04
Initial release
Addition of lead-free and WLP packaging
—
10/08
1, 5, 6, 7, 15
0/MX231AE
Maxim cannot assume responsibilitꢂ for use of anꢂ circuitrꢂ other than circuitrꢂ entirelꢂ embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitrꢂ and specifications without notice at anꢂ time.
±6 ____________________Maxim Integrated -roducts, 120 ꢁan Gabriel Drive, ꢁunnyvale, CA 94086 408ꢂ737ꢂ7600
© 2008 Maxim Integrated Products
is a registered trademark of Maxim Integrated Products, Inc.
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