HAL1000UT-A Datasheet, PDF (7/30 Pages) Micronas – Programmable Hall Switch

DATA SHEET
HAL 1000
A/D
Converter
ADC-READOUT Register
14 bit
Digital Signal Processing
Digital
Filter
Multiplier
Adder
Comparator
Digital
Output
Lock
Control
TC
TCSQ
MODE Register
SENSI-
VOQ
LOW-
HIGH-
LOCKR
Micronas
RANGE FILTER
TIVITY
LEVEL
LEVEL
Registers
6 bit
5 bit
3 bit 3 bit
14 bit
11 bit
10 bit
11 bit
1 bit
EEPROM Memory
Fig. 2–3: Details of EEPROM and Digital Signal Processing
2.2. Digital Signal Processing and EEPROM
The DSP is the main part of the sensor and performs
the signal processing. The parameters for the DSP are
stored in the EEPROM registers. The details are
shown in Fig. 2–3.
Terminology:
SENSITIVITY: name of the register or register value
Sensitivity: name of the parameter
EEPROM Registers:
The EEPROM registers include three groups:
Group 1 contains the registers for the adaption of the
sensor to the magnetic system: MODE for selecting
the magnetic field range and filter frequency, TC and
TCSQ for the temperature characteristics of the mag-
netic sensitivity and thereby for the switching points.
Group 2 contains the registers for defining the switch-
ing points: SENSITIVITY, VOQ, LOW-LEVEL, and
HIGH-LEVEL.
The comparator compares the processed signal volt-
age with the reference values Low-Level and High-
Level.
The output switches on (low) if the signal voltage is
higher than the High-Level, and switches off (high) if
the signal falls below the Low-Level. Several examples
of different switching characteristics are shown in
Fig. 2–4 to Fig. 2–7.
– The parameter V_OQ (Output Quiescent Voltage) cor-
responds to the signal voltage at B = 0 mT.
– The parameter Sensitivity defines the magnetic sen-
sitivity:
Sensitivity =
ΔV_Signal
ΔB
– The signal voltage can be calculated as follows:
V_Signal ∼ Sensitivity × B + V_OQ
Therefore, the switching points are programmed by
setting the SENSITIVITY, VOQ, LOW-LEVEL, and
HIGH-LEVEL registers. The available Micronas soft-
ware calculates the best parameter set respecting the
ranges of each register.
Group 3 contains the Micronas registers and LOCK
for the locking of all registers. The Micronas registers
are programmed and locked during production and are
read-only for the customer. These registers are used
for oscillator frequency trimming, A/D converter offset
compensation, and several other special settings.
Micronas
Feb. 3, 2009; DSH000015_003EN
7