_______________General Description
The MAX3320 combines a microprocessor (µP) super-
visory circuit with an RS-232 transceiver. The power-on
reset performs a single function: it asserts a reset signal
whenever the V
CC
supply voltage declines below a pre-
set threshold, staying asserted for at least 100ms after
V
CC
rises above the reset threshold. The MAX3320 has
an active-low RESET output, which is guaranteed to be in
the correct state for V
CC
down to 1V. The reset compara-
tor is designed to ignore fast transients on V
CC
. Reset
thresholds suitable for operation with a variety of supply
voltages are available.
The MAX3320 transceivers have a proprietary low-
dropout transmitter output stage, enabling true RS-232
performance with a dual charge pump powered from a
+3V to +5.5V supply. The device requires only four
small 0.1µF external charge-pump capacitors, and is
guaranteed to run at data rates of up to 250kbps. It
comes in the space-saving 20-pin SSOP package.
________________________Applications
Palmtop Computers
Portable/Battery-Powered Equipment
Hand-Held Equipment
Peripherals
Printers
____________________________Features
Precise Monitoring of 5V and 3.3V Power-
Supply Voltages:
— 100ms (min) Power-On
RESET Pulse Width
— Power-Supply Transient Immunity
— Guaranteed RESET Valid to V
CC
= 1V
4µA Supply Current Achieved with
AutoShutdown Plus
Receivers Always Active
Power-On Reset Always Active
4µA Low-Power Shutdown
250kbps Guaranteed Data Rate
MAX3320A/B/L/T
3V to 5.5V, up to 250kbps True RS-232 Transceiver
with 4µA AutoShutdown Plus and Power-On Reset
________________________________________________________________
Maxim Integrated Products
1
20
19
18
17
16
15
14
13
1
2
3
4
5
6
7
8
C1+
V
CC
C1-
GNDV-
C2-
C2+
V+
TOP VIEW
T1OUT
T2OUT
R1IN
R2INR2OUT
R1OUT
T2IN
T1IN
12
11
9
10
FORCEON
FORCEOFFRESET
INVALID
MAXxxx
SSOP
MAX3320
__________________Pin Configuration
19-1253; Rev 0; 8/97
PART*
MAX3320_CAP
MAX3320_EAP -40°C to +85°C
0°C to +70°C
TEMP. RANGE PIN-PACKAGE
20 SSOP
20 SSOP
______________Ordering Information
*
This part offers a choice of reset threshold voltage. From the
table below, select the suffix corresponding to the desired
threshold and insert it into the blank to complete the part
number.
AutoShutdown Plus is a trademark of Maxim Integrated Products.
SUFFIX
A
B
RESET THRESHOLD
(V)
4.25
2.85
L 4.63
T 3.08
Typical Operating Circuit appears at end of data sheet.
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 408-737-7600 ext. 3468.
MAX3320A/B/L/T
3V to 5.5V, up to 250kbps True RS-232 Transceiver
with 4µA AutoShutdown Plus and Power-On Reset
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V
CC
= 3V to 5.5V, C1–C4 = 0.1µF (tested at 3.3V ±10%), C1 = 0.047µF, C2–C4 = 0.33µF (tested at 5V ±10%), T
A
= T
MIN
to T
MAX
,
unless otherwise noted. Typical values are at T
A
= +25°C.)
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.
V
CC
.............................................................................-0.3V to 6V
V+ (Note 1) .................................................................-0.3V to 7V
V- (Note 1)...................................................................0.3V to -7V
V+ +
|
V-
|
(Note 1)...................................................................13V
Input Voltages
T_IN, FORCEOFF, FORCEON................................-0.3V to 6V
R_IN.................................................................................±25V
Output Voltages
T_OUT ..........................................................................±13.2V
R_OUT, INVALID, RESET.......................-0.3V to (V
CC
+ 0.3V)
Short-Circuit Duration
T_OUT....................................................................Continuous
Continuous Power Dissipation (T
A
= +70°C)
SSOP (derate 8.00mW/°C above +70°C)....................640mW
Operating Temperature Ranges
MAX3320_CAP...................................................0°C to +70°C
MAX3320_EAP ................................................-40°C to +85°C
Storage Temperature Range.............................-65°C to +160°C
Lead Temperature (soldering, 10sec).............................+300°C
V-0.3 0.3Figure 3
Receiver Input Threshold to
INVALID Output Low
-2.7Figure 3, negative threshold
V
2.7Figure 3, positive threshold
Receiver Input Threshold to
INVALID Output High
k
3 5 7T
A
= +25°CInput Resistance
V0.3Input Hysteresis
1.8 2.4V
CC
= 5V
V
1.5 2.4V
CC
= 3.3V
Input Threshold High
0.8 1.5V
CC
= 5V
V
0.6 1.2V
CC
= 3.3V
Input Threshold Low
V-25 25Input Voltage Range
µA4.0 10
FORCEOFF = GND, T
A
= +25°C
Shutdown Supply Current
mA0.45 1.0No load, V
CC
= 3.3V or 5V, T
A
= +25°CPower-Supply Current
V
V
CC
- V
CC -
0.6 0.1
I
OUT
= -1mAOutput Voltage High
V0.4I
OUT
= 1.6mAOutput Voltage Low
mV250
T_IN, FORCEON, FORCEOFF
Input Hysteresis
µA±0.01 ±1.0
T_IN, FORCEON, FORCEOFF
Input Leakage Current
µA4.0 10
All R_IN unconnected, FORCEON = GND,
FORCEOFF = V
CC
, all T_IN = V
CC
or GND, T
A
= +25°C
AutoShutdown Plus
Supply Current
V0.8
T_IN, FORCEON, FORCEOFF
Input Logic Threshold Low
V
2.0
Input Logic Threshold High
UNITSMIN TYP MAXCONDITIONSPARAMETER
T_IN, FORCEON,
FORCEOFF
2.4
V0.4I
OUT
= 1.6mA
INVALID Output Voltage Low
Note 1: V+ and V- can have a magnitude of +7V (max), but their absolute difference cannot exceed +13V.
V
CC
= 3.3V
V
CC
= 5V
DC CHARACTERISTICS
LOGIC INPUTS AND RECEIVER OUTPUTS
RECEIVER INPUTS
INVALID OUTPUT
MAX3320A/B/L/T
3V to 5.5V, up to 250kbps True RS-232 Transceiver
with 4µA AutoShutdown Plus and Power-On Reset
_______________________________________________________________________________________ 3
sec15 30 60Figure 3
Receiver or Transmitter Edge
to Shutdown
µs25Figure 5
Receiver or Transmitter Edge
to Transmitters Enabled
90 µsFigure 3
Receiver Positive or Negative
Threshold to INVALID Low
µs0.1Figure 3
Receiver Positive or Negative
Threshold to INVALID High
UNITSMIN TYP MAXCONDITIONSPARAMETER
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= 3V to 5.5V, C1–C4 = 0.1µF (tested at 3.3V ±10%), C1 = 0.047µF, C2–C4 = 0.33µF (tested at 5V ±10%), T
A
= T
MIN
to T
MAX
,
unless otherwise noted. Typical values are at T
A
= +25°C.)
V±5.0 ±5.4
All transmitter outputs loaded with 3kto ground
Output Voltage Swing
300 10MV
CC
= V+ = V- = GND, V
T_OUT
= ±2VOutput Resistance
mA±35 ±60T_OUT = GND, T_IN = V
CC
or GNDOutput Short-Circuit Current
µA±25V
T_OUT
= ±12V, V
CC
= 0 to 5.5V, transmitters disabledOutput Leakage Current
V
1.0 5.5MAX3320_C
RESET Operating Voltage
Range
1.2 5.5MAX3320_E
V
4.00 4.25 4.50MAX3320A
RESET Threshold
2.70 2.85 3.00MAX3320B
4.50 4.63 4.75MAX3320L
3.00 3.08 3.15MAX3320T
V
0.3I
SINK
= 1.2mA, V
CC
= reset threshold, MAX3320B/T
RESET Output Voltage
0.4I
SINK
= 3.2mA, V
CC
= reset threshold, MAX3320A/L
0.3I
SINK
= 50µA, V
CC
> 1V, MAX3320_C
0.4I
SINK
= 100µA, V
CC
> 1.2V, MAX3320_E
VV
CC
- 0.6I
OUT
= -1mA
INVALID Output Voltage High
AUTOSHUTDOWN PLUS (FORCEON = GND, FORCEOFF = V
CC
)
TRANSMITTER OUTPUTS
RESET OUTPUT

MAX3320TEAP

Mfr. #:
Manufacturer:
Maxim Integrated
Description:
RS-232 Interface IC 3V to 5.5V, Up to 250kbps True RS-232 Transceiver with 4A AutoShutdown Plus and Power On Reset
Lifecycle:
New from this manufacturer.
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