Human Body Model

Figure 3 shows the Human Body Model, and Figure 4

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

that is then discharged into the device through a 1.5kΩ

resistor.

Chip Information

PROCESS: BiCMOS

Overvoltage Protector with

Active Current Limit

_______________________________________________________________________________________

9

OUT

IN

CONTROL

LOGIC

MAX4978/

MAX4979

BANDGAP

REFERENCE

5V AC

ADAPTER

C0NTROL

CHARGER

CHARGE

PUMP

+

-

+

-

OVLO

UVLO

1

μF

EN

GND

1k

Ω

SDT

PHONE

LOADS

AC-DC

CONVERTER

~0.5

Ω

LONG WIRE

RESISTANCE

nFET

Figure 2. Typical Application Circuit with

SDT

CHARGE CURRENT-

LIMIT RESISTOR

DISCHARGE

RESISTANCE

STORAGE

CAPACITOR

Cs

100pF

1M

Ω

1.5k

Ω

HIGH-

VOLTAGE

DC

SOURCE

DEVICE

UNDER

TEST

Figure 3. Human Body ESD Test Model

90%

36.8%

TIME

CURRENT WAVEFORM

PEAK-TO-PEAK RINGING

(NOT DRAWN TO SCALE)

Ir

10%

0

0

AMPERES

Figure 4. Human Body Current Waveform