AMIS-30521 Datasheet, PDF (10/28 Pages) AMI SEMICONDUCTOR – Micro-stepping Motor Driver

AMIS−30521, NCV70521
TYPICAL APPLICATION SCHEMATIC
V_DD
C₅
100 nF
mC
100 nF
100 nF 100 nF
D1
+
R₂
R₃
C₄
C₂
C₃
C₆
C_{1 100 mF}
VDD
32
VBB
14
VBB
27
220 nF
VCP
11
DIR
NXT
DO
DI
CLK
CS
CLR
ERR
R_{1 SLA}
C₈
9 ^CPN _C7
5
4
10 _CPP ^{220 nF}
31
MOTXP
25,26
2 _{AMIS−30521/}
3
NCV70521 _21,22 MOTXN
13
M
MOTYP
12
15,16
6
19,20 ^MOTYN
7
1, 17, 23,
HV20081114.1
8 18 24 30 28 29
TSTO
GND
Figure 6. Typical Application Schematic AMIS−30521/NCV70521
V_BAT
Table 8. EXTERNAL COMPONENTS LIST AND DESCRIPTION
Component
C₁
C₂, C₃
C₄
C₅
C₆
C₇
C₈
R₁
R₂, R₃
D₁
Function
V_BB Buffer Capacitor (Low ESR < 1 W)
V_BB Decoupling Block Capacitor
V_DD Buffer Capacitor
V_DD Buffer Capacitor
Charge−Pump Buffer Capacitor
Charge−Pump Pumping Capacitor
Low Pass Filter SLA
Low Pass Filter SLA
Pullup Resistor Open Drain Output
Reverse Protection Diode
Typ. Value
100
100
220
100
220
220
1
5.6
4.7
MURD530
Tolerance
Unit
−20 +80%
mF
−20 +80%
nF
$20%
nF
$20%
nF
$20%
nF
$20%
nF
$20%
nF
$1%
kW
$1%
kW
FUNCTIONAL DESCRIPTION
H−Bridge Drivers
A full H−bridge is integrated for each of the two stator
windings. Each H−bridge consists of two low−side and two
high−side N−type MOSFET switches. Writing logic ’0’ in
bit <MOTEN> disables all drivers (High−Impedance).
Writing logic ’1’ in this bit enables both bridges and current
can flow in the motor stator windings.
In order to avoid large currents through the H−bridge
switches, it is guaranteed that the top− and bottom switches
of the same half−bridge are never conductive
simultaneously (interlock delay).
A two−stage protection against shorts on motor lines is
implemented. In a first stage, the current in the driver is
limited. Secondly, when excessive voltage is sensed across
the transistor, the transistor is switched−off.
In order to reduce the radiated/conducted emission,
voltage slope control is implemented in the output switches.
The output slope is defined by the gate−drain capacitance of
output transistor and the (limited) current that drives the
gate. There are two trimming bits for slope control (See
Table 12 SPI Control Parameter Overview EMC[1:0]).
The power transistors are equipped with so−called “active
diodes”: when a current is forced trough the transistor switch
in the reverse direction, i.e. from source to drain, then the
transistor is switched on. This ensures that most of the
current flows through the channel of the transistor instead of
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