UBA2211AP PHILIPS [NXP Semiconductors], UBA2211AP Datasheet - Page 5

• Manufacturer Part Number: UBA2211AP
• Description: Half-bridge power IC family for CFL lamps
• Manufacturer: PHILIPS [NXP Semiconductors]

NXP Semiconductors
7. Functional description
UBA2211
Product data sheet
7.1 Supply voltage
7.2 Start-up state
7.3 Reset
7.4 Oscillation control
The UBA2211 family is powered using a start-up current source and a DVDT supply.
When the voltage on pin HV increases, the V
internal Junction gate Field-Effect Transistor (JFET) current source. The voltage on pin
V
half-bridge starts switching causing the charge pump to generate the required V
The amount of current flowing towards V
momentary frequency. The charge pump consists of an external half-bridge capacitor
(C
Mount these diodes externally with the DIP8 packaged devices. The Zener diode ensures
the V
The DVDT supply has its own ground pin (PGND) to prevent large peak currents from
flowing through the external small signal ground pin (SGND).
The start-up current source is enabled when the voltage on pin V
level.
When the supply voltage on pin V
start-up state the High-Side Power Transistor (HSPT) is switched off and the Low-Side
Power Transistor (LSPT) is switched on. The circuit is reset and the capacitors on the
bootstrap pin FS (C
and SW are switched to ground.
When pin V
entered. If the voltage on pin V
state.
Remark: If OTP is active, the IC remains in the start-up state indefinitely. The V
slowly oscillates between V
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.
The oscillation frequency is based on the 555-timer function. A self oscillating circuit is
created comprising the external components: resistors R
R
An internal divider 0.5  f
divider sets the bridge frequency at half the oscillator frequency.
The input on pin SW generates the V
all states except preheat. Signal V
determine the frequency during the preheat state.
DD
osc
DVDT
rises until V
and C
DD
). The SO14 package contains two internal diodes with an internal Zener diode.
voltage cannot rise above the maximum V
osc
DD
determine the nominal oscillating frequency.
is above V
All information provided in this document is subject to legal disclaimers.
DD
equals V
bs
) and the low-voltage supply pin V
Rev. 3 — 26 August 2011
osc(int)
DD(start)
DD
DD(start)
= V
DD
is used to generate the accurate 50 % duty cycle. The
, the start-up state is exited and the preheat state is
DD
falls below V
DD(stop)
SW(ph)
. The start-up current source is then disabled. The
SW
increases, the IC enters the start-up state. In the
signal and it is used to determine the frequency in
DD
is an internally generated signal used to
and V
equals V
Half-bridge power IC family for CFL lamps
DD
DD(stop)
DD
capacitor (C
= V
DD
HV
, the system returns to the start-up
rating.
DD(start)
 C
DD
osc
DVDT
(C
, R
VDD
.
VDD
SENSE
 f where f represents the
) is charged using the
DD
) are charged. Pins RC
is below the V
and capacitor C
UBA2211
© NXP B.V. 2011. All rights reserved.
DD
DD
voltage
supply.
DD(stop)
5 of 20
osc
.