NXP Semiconductors
UBA2016A/15/15A
600 V fluorescent lamp driver
The amount of boost depends on the current into the BOOST pin and the lamp current
control. If the application does not use lamp current control, the switching frequency will
go down to the lowest possible boost switching frequency fsw(bst)(low) (point G in Figure 11
“Resonance curve application with UBA2016A”) that is determined by Equation 1 or
Equation 2, depending on the value of IBOOST.
0 IBOOST IsatBOOST fswbstlow = fswlow1 – IBOOST Nfbstlow
(1)
IBOOST IsatBOOST fswbstlow = fswlow1 – IsatBOOST Nfbstlow
(2)
If the application uses lamp current control, the switching frequency is regulated to boost
regulation voltage on pin IFB, Vreg(bst)(IFB) (point F in Figure 11 “Resonance curve
application with UBA2016A”) that can be calculated by Equation 3 or Equation 4,
(depending on the value of IBOOST) if the switching frequency remains above fsw(bst)(low),
otherwise the switching frequency is fsw(bst)(low); see Equation 1 or Equation 2.
0 IBOOST IsatBOOST VregIFBIBOOST = VregIFB1 + IBOOST Nlbstreg
(3)
IBOOST IsatBOOST VregbstIFB = VregIFB + IsatBOOST NVregbst
(4)
7.4.8 Stop state
When in Stop state the IC is off and all driver outputs are low. The IC will remain in Stop
state until the voltage on pin VDD drops below Vrst(VDD) or it is disabled, in which case it
will go to Reset state.
The sequence of events for entering the Stop state are shown in Figure 9 “State diagram”.
7.5 Enable and Disable
The enable function is only available in the UBA2015 and UBA2015A and works via pin
PH/EN. If this pin is pulled below the enable voltage Ven(PH/EN) then the IC goes into the
Standby state (immediately if GLHB is high, otherwise it will continue its normal clock
cycle until GLHB is high and then go to the Standby state).
The external interface with pin PH/EN for the enable signal should be an open collector or
open drain type driver. To enable the IC the open collector or open drain should be open
(high ohmic) to not disturb the fixed frequency preheat setting function of pin PH/EN.
In Restart, Standby and Stop states the standby pull-up current source Ipu(stb)(PH/EN) will
pull the voltage at pin PH/EN above Ven(PH/EN). In Preheat, Ignition and Burn states the
normal output voltage driver of the IC will pull the pin high. In those cases the external
driver must draw a current Iclamp(PH/EN) from the pin to disable the IC.
7.6 Protection circuits
7.6.1 End-of-life rectifying lamp detection
If voltage on pin EOL is below low threshold voltage Vth(low)EOL or above Vth(high)EOL the
fault timer will start. These threshold voltage levels are related to pin FBPFC voltage
according to the formula: Vth(low)EOL = VFBPFC = Vth(high)EOL / 2. The FBPFC voltage is
sampled during GPFC low and hold during GPFC high periods to prevent disturbance of
the EOL levels due to the switching of the PFC.
UBA2016A_15_15A
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 16 November 2011
© NXP B.V. 2011. All rights reserved.
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