MAX3235EEPP Maxim Integrated Products, MAX3235EEPP Datasheet - Page 10
Manufacturer Part Number
IC TXRX RS232 DUAL 250KBPS 20DIP
Maxim Integrated Products
Specifications of MAX3235EEPP
Number Of Drivers/receivers
Voltage - Supply
4.5 V ~ 5.5 V
Package / Case
20-DIP (0.300", 7.62mm)
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
±15kV ESD-Protected, 1µA, 250kbps, 3.3V/5V, Dual
RS-232 Transceivers with Internal Capacitors
that measured using the Human Body Model. Figure 6a
shows the IEC 1000-4-2 model, and Figure 6b shows the
current waveform for the ±8kV, IEC 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.
The Machine Model for ESD tests all pins using a
200pF storage capacitor and zero discharge resis-
tance. Its objective is to emulate the stress caused by
contact that occurs with handling and assembly during
Figure 7. Transmitter Outputs when Exiting Shutdown or
Figure 6b. IEC 1000-4-2 ESD Generator Current Waveform
t r = 0.7ns to 1ns
FORCEON = FORCEOFF
manufacturing. Of course, all pins require this protec-
tion during manufacturing, not just RS-232 inputs and
outputs. Therefore, after PC board assembly, the
Machine Model is less relevant to I/O ports.
The MAX3233E/MAX3235E do not require external
capacitors to operate their internal charge pumps.
The MAX3235E can be operated down to 3.0V by par-
alleling the internal C1 capacitor with an external 0.1µF.
When using an external capacitor across the C1 termi-
nals, check to confirm that the total supply voltage
measured from V+ to V- does not exceed the absolute
maximum voltage of 13V. With the external 0.1µF
capacitor added, the MAX3235E should not be used
with a supply greater than +3.9V.
In most applications, a 0.1µF V
adequate. Connect bypass capacitors as close to the
IC as possible.
Figure 7 shows two transmitter outputs when exiting
shutdown mode. As they become active, the two trans-
mitter outputs are shown going to opposite RS-232
levels (one transmitter input is high, the other is low).
Figure 8. Loopback Test Circuit
when Exiting Shutdown
bypass capacitor is