A4960-A Datasheet, PDF (27/34 Pages) Allegro MicroSystems – Automotive, Sensorless BLDC Controller

A4960
Automotive, Sensorless BLDC Controller
Serial Register Reference
15
14
13
12
11
10
Config 2 (PWM)
0
1
0 WR
Config 3 (Hold)
0
1
1 WR
*Power on reset value shown below each input register bit.
9
8
7
6
5
4
3
2
1
0
PT4 PT3 PT2 PT1 PT0
1
0
0
0
0
IDS HQ3 HQ2 HQ1 HQ0 HT3 HT3 HT1 HT0
0
0
1
0
1
0
1
0
0
Configuration Register 2
PT[4:0] Fixed off time
t_OFF = 10 µs ₊(n _× 1.6µs)
where n is a positive integer defined by PT[4:0]
e.g. for the power-on-reset condition
PT[4:0] = [1 0 0 0 0] then t_OFF=35.6µs
The range of t_OFF is 10µs to 59.6µs.
The accuracy of t_OFF is determined by the system clock
frequency as defined in the electrical characteristics table.
Configuration Register 3
IDS
IDS
0
1
Start-up Torque control method
Start-up Torque control
Current limited
Duty cycle limited
Default
D
HQ[3:0]
Current sense reference ratio or duty cycle ratio
for hold torque during initial start sequence.
If IDS is 0 then HQ[3:0] sets the hold current.
If IDS is 1 then HQ[3:0] sets the hold duty cycle.
Typically:
V_RH = ₍ n + 1₎× 6.25 %V_REF ...... when IDS=0
D _H = ₍n + 1 ₎× 6.25 % ............... when IDS=1
where n is a positive integer defined by HQ[3:0]
e.g. for the power-on-reset condition
HQ[3:0] = [0 1 0 1] then
V_RH=37.5%V_REF ...................... when IDS=0
D_H=37.5% ............................... when IDS=1
The range of V_RH is 6.25% V_REF to 100%V_REF.
The range of D_H is 6.25% to 100%.
The accuracy of V_RH and D_H is defined in the electrical
characteristics table.
HT[3:0] Hold Time.
t _HOLD = 2ms +₍n × 8 ms₎
where n is a positive integer defined by HT[3:0]
e.g. for the power-on-reset condition
HT[3:0] = [0 1 0 0] then t_HOLD=34ms
The range of t_HOLD is 2ms to 122ms.
The accuracy of t_HOLD is determined by the system clock
frequency as defined in the electrical characteristics table.
Allegro MicroSystems, LLC
27
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com