DRV8808 Datasheet, PDF (18/38 Pages) Texas Instruments – COMBINATION MOTOR DRIVER WITH DC-DC CONVERTER

DRV8808
SLVS857A – DECEMBER 2009 – REVISED AUGUST 2011
www.ti.com
DC Motor Drive
H-bridges A, B, and C can be controlled by using the ENABLE_X and PHASE_X control lines.
The H-bridge driver operation is available for V_M > 15 V.
Internal current sense functionality is present by default. External sensing can be enabled through the serial
interface. If enabled, the sense resistor must be placed externally.
NOTE
A capacitor, not larger than 2200 pF, can be placed between each H-bridge output to
GND for EMI suppression purposes. It will increase the peak current but will have no
impact on the operation.
Enable or Phase Reversal
or Trip Reduction
Sink or Source Gate
OFF to ON
Sink or Source Gate
ON to OFF
t_PDON
t_PDOFF
t_COD
Current Sense
Blanking Time
t : _BLANK DC Motor
Figure 7. Crossover and Blanking Timing for H-Bridge
The dc motor H-bridges include a tBLANK period to ignore huge current spike due to rush current to varistor
capacitance.
Short/Open for Motor Outputs
When a short/open situation happens, the protection circuit prevents device damage under certain conditions
(short at start-up, etc).
Shutdown is released based on MISD Control in the Extended Setup register.
FAULT
CONDITION
0
0
0
0
Motor OCP
TSD
(1) X = Don't care
nSleep
0
1
1
1
X
X
Table 7. DC Motor-Drive Truth Table ⁽¹⁾
Enablex
X
0
1
1
X
X
Phasex
X
X
0
1
X
X
+ HIGH SIDE
OFF
OFF
OFF
ON
OFF
OFF
+ LOW SIDE
OFF
OFF
ON
OFF
OFF
OFF
– HIGH SIDE
OFF
OFF
ON
OFF
OFF
OFF
– LOW SIDE
OFF
OFF
OFF
ON
OFF
OFF
18
Copyright © 2009–2011, Texas Instruments Incorporated