uba2030t-n1 NXP Semiconductors, uba2030t-n1 Datasheet - Page 6

• Manufacturer Part Number: uba2030t-n1
• Description: Full Bridge Driver Ic
• Manufacturer: NXP Semiconductors

Philips Semiconductors
FUNCTIONAL DESCRIPTION
Supply voltage
The UBA2030T is powered by a single supply voltage
connected to the HV pin (the full bridge supply could be
used, for example). The IC generates its own low voltage
supply for driving the internal circuitry and the MOSFETs
in the full bridge, removing the need for an additional low
voltage supply. A capacitor must be connected between
the V
supply voltage.
Start-up
When the power is turned on, the UBA2030T enters a
start-up phase; the high side MOSFETs are switched off
and the low side MOSFETs switched on. During start-up,
the bootstrap capacitors are charged and the bridge output
current is zero.
Oscillation
At the point where the supply voltage at the HV pin crosses
the ‘start oscillating threshold’, the bridge begins
commutating between the following two defined states:
When the internal oscillator is used, the bridge
commutating frequency is determined by the values of an
external resistor and capacitor. In this mode, the EXO pin
must be connected to SGND.
2002 Sep 27
Higher left and lower right MOSFETs on and higher right
and lower left MOSFETs off
Higher left and lower right MOSFETs off and higher right
and lower left MOSFETs on.
Full bridge driver IC
DD
pin and SGND to obtain a ripple-free internal
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When an external oscillator is used, its output must be
connected to the EXO pin; the internal oscillator must be
disabled by connecting the RC pin to SGND. The bridge
commutating frequency is half the oscillator frequency due
to a 2 circuit which guarantees an accurate 50% duty
factor.
The time between turning off the conducting pair of
MOSFETs and turning on the other pair, the ‘dead time’,
can be adjusted using an external resistor. If the supply
voltage at the HV pin falls below the ‘stop oscillating
threshold’, the UBA2030T re-enters the start-up phase.
Bridge enable
The bridge enable function allows the bridge to be held in
its current state. When active, it connects the RC pin to
SGND, disabling the internal oscillator. If the bridge enable
function is activated during ‘dead time’, the bridge is
allowed to enter the next conducting state before being
held. Oscillations resume the instant the bridge enable
function is turned off. A timing diagram is shown in Fig.3.
To hold the bridge, an external control circuit is required to
provide a source current to the bridge enable control input
(pin BE), and to supply a reference voltage to pin BER
(see Fig.6).
Shut-down
The active HIGH shut-down input (pin SD) can be used at
any time to turn off all four MOSFETs. However, if the
supply voltage drops below the ‘stop oscillating threshold’,
the bridge re-enters the start-up phase even if the
shut-down function is active.
Product specification
UBA2030T