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- 6 -
Nov. 2004
(Rev. 1)
IP4001S 5-CH MOTOR DRIVE IC
APPLICATION SUMMARY (Continued)
-
Tray motor drive part
CH5 is a forward/reverse controlled DC motor driver for tray motor. The forward or reverse movement of the
tray motor is controlled by the pins 9 and 14. The output voltage status according to the control input conditions
are shown in the table. The magnitude of the differential output voltage is determined by the control current
generator. The control input voltage, VCTL at the pin20 approximately appears across R1 and hence the control
current,
i
is VCTL/R1. This current enters into the control current distributor, which generates two output
currents,
i
1 and
i
2. The magnitude of
i
1 and
i
2 are equal each other and is the same as
i
. When the pin9
is high and the pin14 is low, the direction of the current flow of
i
1 and
i
2 are the same direction as shown in Fig.
5. On the contrary, when the pin9 is low and the pin14 is high, the direction of
i
1 and
i
2 are reversed. If both
the pins 9 and 14 are high or low at the same time,
i
1 and
i
2 become to be zero and the tray motor is in the
brake mode. When the output is not in the brake mode, the magnitude of the differential output voltage and the
CTL-to-output transfer gain are given as in the following equations. The resistors, R1 and R2 are selected such
that Gv has a typical value of 1.0 V/V. Rb1 and Rb2 are used for setting the output voltage when the pin20 is
open circuited. The typical output voltage as the pin20 is opened is about 3.1V for the supply voltage of 8V.
INPUT
FWD(PIN9)
REV(PIN14)
DO5+(PIN15)
DO5-(PIN16)
STATUS
High
High
Vpref
Vpref
Brake
High
Low
High
Low
Forward
Low
High
Low
High
Reverse
Low
Low
Vpref
Vpref
Brake
OUTPUT
CTL
G v =
R 2
R 1
Vo
Vo = 2
CTL
R2
R1
= 2
Fig. 3. Tray drive part
VCTL
R1
Δ
i=
Vo5+ =Pref - VCTLR2
Vo5- =Pref +VCTLR2