MAX3323EEUE Maxim Integrated, MAX3323EEUE Datasheet - Page 8

• Manufacturer Part Number: MAX3323EEUE
• Description: RS-232 Interface IC
• Manufacturer: Maxim Integrated
• Series: MAX3322E, MAX3323Er

Specifications of MAX3323EEUE

• Data Rate: 250 Kbps
• Operating Supply Voltage: 3 V to 5.5 V
• Supply Current: 1 mA
• Operating Temperature Range: - 40 C to + 85 C
• Function: Transceiver
• Number Of Drivers: 1
• Number Of I/os: 4
• Number Of Receivers: 1
• Propagation Delay Time Ns: 0.18 us, 0.7 us
• Shutdown: Yes

The IEC 1000-4-2 standard covers ESD testing and
performance of finished equipment; it does not refer
specifically to integrated circuits. The MAX3322E/
MAX3323E help the user design equipment that meets
level 4 of IEC 1000-4-2, without the need for additional
ESD-protection components. The major difference
between tests done using the Human Body Model and
IEC 1000-4-2 is a higher peak current in IEC 1000-4-2,
because series resistance is lower in the IEC 1000-4-2
model. Hence, the ESD withstand voltage measured to
IEC 1000-4-2 is generally lower than that measured
using the Human Body Model. Figure 7 shows the IEC
1000-4-2 model. Figure 8 shows the current waveform it
generates when discharged into a low impedance. The
Air-Gap Discharge 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
manufacturing. All pins require this protection during
manufacturing. Therefore, after PC board assembly, the
Machine Model is less relevant to I/O ports.
The capacitor type used for C1–C4 is not critical for
proper operation; polarized or nonpolarized capacitors
can be used. The charge pump requires 0.1µF capaci-
tors for 3.3V operation. For other supply voltages, see
Table 2 for required capacitor values. Do not use val-
ues smaller than those listed in Table 2. Increasing the
capacitor values (e.g., by a factor of 2) reduces ripple
±15kV ESD-Protected, RS-232 Transceivers for
Multidrop Applications
Figure 5. Human Body ESD Test Model
8
VOLTAGE
SOURCE
____________________________________________________
HIGH-
DC
CHARGE-CURRENT-
LIMIT RESISTOR
1MΩ
R
Applications Information
C
100pF
C s
RESISTANCE
DISCHARGE
STORAGE
CAPACITOR
1.5kΩ
R
D
Machine Model
IEC 1000-4-2
DEVICE
UNDER
TEST
Figure 6. Human Body Model Current Waveform
Figure 7. IEC 1000-4-2 ESD Test Model
Figure 8. IEC 1000-4-2 ESD Generator Current Waveform
AMPERES
t r = 0.7ns TO 1ns
VOLTAGE
SOURCE
HIGH-
DC
I
P
36.8%
100%
90%
10%
CHARGE-CURRENT-
0
100%
LIMIT RESISTOR
90%
10%
0
I
50Ω to 100Ω
t
RL
R
150pF
C
C s
30ns
STORAGE
CAPACITOR
CURRENT WAVEFORM
TIME
RESISTANCE
DISCHARGE
330Ω
R
D
t
60ns
DL
I r
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
DEVICE
UNDER
TEST
t