A1363 Datasheet, PDF (14/30 Pages) Allegro MicroSystems – Low Noise, High Precision, Programmable Linear Hall Effect Sensor IC

A1363
Low Noise, High Precision, Programmable Linear Hall Effect Sensor IC
With Advanced Temperature Compensation
And High Bandwidth (120 kHz) Analog Output
Initial Unprogrammed Quiescent Voltage Output
( V_{OUT(Q)init } )
Before any programming, the Quiescent Voltage Output,
V_OUT(Q) , has a nominal value of V_CC / 2, as shown in Figure 5.
Quiescent Voltage Output Programming Range
( V_OUT(Q)PR )
The Quiescent Voltage Output, V_OUT(Q) , can be programmed
within the Quiescent Voltage Output Range limits: V_OUT(Q)PR
(min) and V_OUT(Q)PR (max). Exceeding the specified Quiescent
Voltage Output Range will cause Quiescent Voltage Output Drift
Through Temperature Range ΔV_OUT(Q)TC to deteriorate beyond
the specified values, as shown in Figure 5.
Average Quiescent Voltage Output Programming Step Size
(Step_VOUT(Q))
The Average Quiescent Voltage Output Progamming Step Size,
Step_VOUT(Q) , is determined using the following calculation:
Step_VOUT(Q)
=
V_{OUT(Q)maxcode} –V_{OUT(Q)mincode}
2ⁿ–1
,
(1)
where n is the number of available programming bits in the trim
range, 9 bits, V_{OUT(Q)maxcode} is at decimal code 255, and V_OUT(Q)
mincode ^{is at decimal code 256.}
V
V_CLP(HIGH)
Magnetic Input
t_CLP
t₁
t₂
V_OUT
t₁=
time at which output voltage
reaches steady state clamp
initially
voltage
t₂= time at which output voltage settles to
within 1% of steady state clamp voltage
Note: Times apply to both high clamp
(shown) and low clamp.
0
t
Figure 4: Delay to Clamp Definition
Quiescent Voltage Output Programming Resolution
(Err_PGVOUT(Q) )
The programming resolution for any device is half of its pro-
gramming step size. Therefore, the typical programming resolu-
tion will be:
Err_PGVOUT(Q)(typ) = 0.5 × Step_VOUT(Q)(typ)
(2)
Quiescent Voltage Output Temperature Coefficient
(TC_QVO)
Device V_OUT(Q) changes as temperature changes, with respect to
its programmed Quiescent Voltage Output Temperature Coef-
ficient, TC_QVO . TC_QVO is programmed at 150°C, and calculated
relative to the nominal V_OUT(Q) programming temperature of
25°C. TC_QVO (mV/°C) is defined as:
TC_QVO = [V_OUT(Q)T2 – V_OUT(Q)T1][1/(T2-T1)]
(3)
where T1 is the nominal V_OUT(Q) programming temperature of
25°C, and T2 is the TC_QVO programming temperature of 150°C.
The expected V_OUT(Q) through the full ambient temperature
range, V_{OUT(Q)EXPECTED(TA) }, is defined as:
V_{OUT(Q)EXPECTED(TA)} = V_OUT(Q)T1 + TC_QVO(T_A –T1) (4)
V_{OUT(Q)EXPECTED(TA)} should be calculated using the actual mea-
sured values of V_OUTQ)T1 and TC_QVO rather than programming
target values.
V_OUT(Q)PR(min)
value
V_OUT(Q)
V_OUT(Q)PR(max)
value
Programming range
(specified limits)
Distribution of values
resulting from minimum
programming code
(QVO programming bits
set to decimal code 256)
Typical initial value before
customer programming
V_OUT(Q)init
(QVO programming
bits set to code 0)
Distribution of values
resulting from maximum
programming code
(QVO programming bits
set to decimal code 255)
Figure 5: Quiescent Voltage Output Range Definition
Allegro MicroSystems, LLC
14
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com