3250
PROGRAMMABLE, CHOPPER-
STABILIZED, PRECISION,
HALL-EFFECT SWITCH
PROGRAMMING PROTOCOL
The A3250x operate point and A3251x release point are
programmed by serially addressing the device through the
supply terminal (pin1). After the correct operate/release
point is determined, the device programming bits are
selected and then a “lock” set to prevent any further
(accidental) programming.
VPP
PROGRAM ENABLE
(AT LEAST 7 PULSES)
Program Enable. To program the device, a sequence of
pulses is used to activate/enable the addressing mode as
shown in figure 1. This sequence of a VPP pulse, at least
seven VPH pulses, and a VPP pulse with no supply interrup-
tions, is designed to prevent the device from being pro-
grammed accidentally (for example, as a result of noise on
the supply line).
V
PH
V
PL
t
d(1)
t
d(1)
td(0)
0
Dwg. WH-013
Figure 1 — Program enable
PROGRAMMING PROTOCOL over operating temperature range.
Limits
Characteristic
Symbol
VPL
VPH
VPP
IPP
Description
Min.
4.5
9.0
20
Typ. Max.
Units
V
Programming Voltage
Minimum voltage during programming
5.0
10
5.5
11
25
—
—
—
—
—
—
V
23
V
Programming Current
Pulse Width
Max. supply current during programming
OFF time between bits
—
250
—
mA
µs
µs
µs
µs
µs
td(0)
td(1)
tdP
20
Enable, address, program, or lock bit ON time
Program pulse ON time
20
—
100
11
300
—
Pulse Rise Time
Pulse Fall Time
tr
VPL to VPH or VPP
tf
VPH or VPP to VPL
5.0
—
NOTE: Typical data is at TA = +25°C and is for design information only.
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