UBA2032T PHILIPS [NXP Semiconductors], UBA2032T Datasheet - Page 6

• Manufacturer Part Number: UBA2032T
• Description: Full bridge driver IC
• Manufacturer: PHILIPS [NXP Semiconductors]

Philips Semiconductors
The oscillation can take place in three different modes:
If the supply voltage on pin V
reset level of power drive, the UBA2032 re-enters the
start-up phase. The design equation for the bridge
oscillator frequency is:
Non-overlap time
The non-overlap time is the time between turning off the
conducting pair of MOSFETs and turning on the next pair.
The non-overlap time is realized by means of an adaptive
non-overlap circuit. With an adaptive non-overlap, the
application determines the duration of the non-overlap and
makes the non-overlap time optimal for each frequency.
The non-overlap time is determined by the duration of the
falling slope of the relevant half bridge voltage (see Fig.4).
The occurrence of a slope is sensed internally. The
minimum non-overlap time is internally fixed.
2002 Oct 07
Internal oscillator mode.
In this mode the bridge commutating frequency is
determined by the values of an external resistor (R
and capacitor (C
connected to pin +LVS. To realize an accurate 50% duty
factor, the internal divider should be used. The internal
divider is enabled by connecting pin DD to SGND. Due
to the presence of the divider the bridge frequency
is half the oscillator frequency. The commutation of the
bridge will take place at the falling edge of the signal on
pin RC. To minimize the current consumption
pins +LVS, LVS and EXTDR can be connected
together to either pin SGND or V
current source in the logic voltage supply circuit is shut
off.
External oscillator mode without the internal divider.
In the external oscillator mode the external source is
connected to pin EXTDR and pin RC is short-circuited to
pin SGND to disable the internal oscillator. If the internal
divider is disabled (DD = V
bridge output signal is determined by the external
oscillator signal and the bridge frequency equals the
external oscillator frequency.
External oscillator mode with the internal divider.
The external oscillator mode can also be used with the
internal divider function enabled (RC = DD = SGND).
Due to the presence of the divider the bridge frequency
is half the external oscillator frequency. The
commutation of the bridge is triggered by the falling
edge of the EXTDR signal with respect to V
Full bridge driver IC
osc
). In this mode pin EXTDR must be
f
bridge
DD
DD
=
) the duty factor of the
or HV drops below the
--------------------------------------------------
k
osc
DD
. In this way the
R
osc
1
C
LVS
osc
.
.
osc
)
6
Divider function
If pin DD = SGND then the divider function is
enabled/present. If the divider function is present there is
no direct relation between the position of the bridge output
and the status of pin EXTDR.
Start-up delay
Normally, the circuit starts oscillating as soon as pin V
HV reaches the level of release power drive. At this
moment the gate drive voltage is equal to the voltage on
pin V
high side transistors. If this voltage is too low for sufficient
drive of the MOSFETs the release of the power drive can
be delayed via pin SU. A simple RC filter (R between
pins V
used to make a delay, or a control signal from a processor
can be used.
Bridge disable
The bridge disable function can be used to switch off all the
MOSFETs as soon as the voltage on pin BD exceeds the
bridge disable voltage (1.29 V). The bridge disable
function overrules all the other states.
handbook, halfpage
Fig.4
V half bridge right
V half bridge left
DD
DD
for the low side transistors and V
and SU; C between pins SU and SGND) can be
Half bridge and higher/lower side driver
output signals.
V GHR
V SHR
V GHL
V SHL
0
0
0
0
Preliminary specification
DD
UBA2032
0.6 V for the
t (sec)
MGU545
DD
or