ucn5829 Allegro MicroSystems, Inc., ucn5829 Datasheet - Page 9

• Manufacturer Part Number: ucn5829
• Description: 9-bit Serial-input, Latched Sink Driver
• Manufacturer: Allegro MicroSystems, Inc.

operation at higher than allowable current levels, V
exceed 3.2 V, except to disable the chopping function.
be between 15% and 50% with 20% to 40% recommended. The lower
limit is due to internal lockout circuitry while the upper limit guarantees
synchronous operation. The duty cycle (dc) can be calculated as
where I
should be connected to IN
devices (eight channels per device) are cascaded by connecting
SERIAL DATA OUT to the next SERIAL DATA IN.
TTL compatibility.
output. Fast recovery diodes are recommended to reduce power
dissipation in the UCN5829EB. Internal filtering prevents false trigger-
ing of the current sense comparator which can be caused by the
recovery current spike of the diodes when the outputs turn ON.
placed as close as possible to the device. Internal power-ON reset
circuitry prevents false output triggering during power up.
at a junction temperature of typically +165 C. The thermal shutdown is
independent of all other functions. It should not be used as another
control input but is intended only to protect the chip from catastrophic
failures due to excessive junction temperatures. The output drivers are
re-enabled when the junction temperature cools down to approximately
+145 C.
The chopping function is disabled when V
For most practical cases, correct operation can be achieved if
I
Each of the CMOS logic inputs have internal pull-up resistors for
An external transient-protection flyback diode is required at each
The SUPPLY terminal should be well decoupled with a capacitor
Thermal protection circuitry is activated and turns OFF all drivers
OUT(asym)
v
v
For correct operation of the UCN5829EB, the duty cycle must
For applications with 9-wire printheads, SERIAL DATA OUT
OUT(asym)
d
c
= discharge voltage across the load = V
= charge voltage across the load = V
/ I
dc =
OUT(P)
= the asymptotic current value = v
> 2.5.
t
on
LATCHED SINK DRIVER
t
on
+ t
9
off
. For 24-wire printhead applications, three
9-BIT SERIAL-INPUT,
I
OUT(P)
/ I
1 + v
OUT(asym)
d
REF
/ v
c
+ v
BB
> 4.5 V. To prevent
REF
- V
HSD
d
c
/ v
/R
should not
OUT(SAT)
c
+ V
L
DIODE
5829
- V
HSD