UBA2024AP NXP [NXP Semiconductors], UBA2024AP Datasheet - Page 3

• Manufacturer Part Number: UBA2024AP
• Description: Half-bridge power IC for CFL lamps
• Manufacturer: NXP [NXP Semiconductors]

NXP Semiconductors
7. Functional description
UBA2024_4
Product data sheet
6.2 Pin description
7.1 Supply voltage
7.2 Start-up state
7.3 Sweep mode
7.4 Reset
Table 2.
The UBA2024 does not require an external low-voltage supply as the mains supply
voltage applied to pin HV powers it. The IC derives its own low supply voltage from this for
its internal circuitry.
With an increase of the supply voltage on pin HV, the IC enters the start-up state. In the
start-up state the high-side power transistor is not conducting and the low-side power
transistor is switched on. The internal circuit is reset and the capacitors on the bootstrap
pin FS and low-voltage supply pin V
ground. The start-up state is defined until V
The IC enters the sweep mode when the voltage on pin V
on pin SW is charged by I
the start-up state again when the voltage on pin V
The sweep time (t
capacitor (C
During the sweep time the current flowing through the lamp electrodes performs some
preheating of the filaments. See
A DC reset circuit is incorporated in the high-side driver. The high-side transistor is
switched off when the voltage on pin FS is below the high-side lockout voltage V
t
Symbol
SW
SGND
FS
PGND
OUT
HV
V
RC
sweep
DD
=
C
Pin description
SW
SW
Pin SOT97-1 Pin SOT108-1 Description
1
2
3
4
5
6
7
8
nF
). Typical the total sweep time set by C
sweep
10.3ms
Rev. 04 — 17 September 2009
) is determined by the charge current (I
SW
8
10, 13
11
4
7
1, 2, 3, 5, 9,
12
14
6
and the half-bridge circuit starts oscillating. The circuit enters
Figure
DD
are charged. Pins RC and SW are switched to
5.
sweep timing input
signal ground
high-side floating supply output
power ground
half-bridge output
high-voltage supply
internal low-voltage supply output
internal oscillator input
DD
= V
DD(startup)
DD
Half-bridge power IC for CFL lamps
SW
V
DD(stop)
is:
DD
.
ch(sw)
V
.
DD(startup)
) and the external
UBA2024
© NXP B.V. 2009. All rights reserved.
. The capacitor
float(UVLO)
3 of 14
(1)
.