uba20271 NXP Semiconductors, uba20271 Datasheet - Page 16

• Manufacturer Part Number: uba20271
• Description: 350 V And 600 V Power Ics For Dimmable Compact Fluorescent Lamps
• Manufacturer: NXP Semiconductors

NXP Semiconductors
UBA20271_UBA20272
Product data sheet
7.4.5 Power-down mode
7.4.6 OverTemperature Protection (OTP)
Power-down mode starts when:
In power-down mode, the oscillator is stopped and the HS transistor is non-conductive
while the LS transistor is conductive. The V
released from power-down mode by lowering the low voltage supply lower than V
(mains switch reset).
An option exists to set the IC in power-down mode via external logic. The external
power-down option is only available when the IC is in the boost or burn state. To enable
the external power-down option, the CP pin is used. When pin CP, is connected via a
10 k resistor to either the PGND or SGND the voltage on pin CP is pulled down lower
than V
Remark: Do not connect the CP pin directly to the SGND or PGND pin. Connect the
SGND or PGND pin via a series 10 kresistor otherwise excessive currents flow during
reset and start-up. Excessive current prevent the IC from starting up.
The OTP circuit is designed to prevent the IC from overheating in hazardous
environments. The circuit is triggered when the IC temperature exceeds the maximum
temperature value T
V
(=T
otp(CSI)
•
•
•
j(otp)hys
a continuous overcurrent exceeds the maximum overcurrent time-out t
a longer period when an overcurrent occurs in more than half the number of cycles
V
during the boost or the burn state f
detection
two consecutive failed lamp ignition attempts occur
th(CP)min
th(pd)CP
level. This condition remains until the IC temperature reduces by 20 C
) and returns to the DCI controlled level.
. This results in the IC entering power-down mode.
is reached.
All information provided in this document is subject to legal disclaimers.
350 V and 600 V Power ICs for dimmable compact fluorescent lamps
j(otp)
Rev. 2 — 8 September 2011
. OTP changes the lamp current to the level that corresponds to
bridge(max)
DD
supply is internally clamped. The circuit is
is reached due to capacitive mode
UBA20271/2
© NXP B.V. 2011. All rights reserved.
fault(oc)
.Or over
DD(rst)
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