SSL5235TE
Mains dimmable buck-boost LED driver IC 5 Ohm/550 V
Rev. 1 — 13 March 2015
Product data sheet
1. General description
The SSL5235TE is a highly integrated, high-precision buck-boost controller with an
internal MOSFET. It is intended to drive low-cost compact dimmable LED lamps up to
12 W. The SSL5235TE is designed to achieve high power factor, phase-dimmable
applications.
The SSL5235TE operates in Boundary Conduction Mode (BCM) with constant on-time
control. It regulates a constant output current over line and load variations. The wide
switching frequency range makes it possible to choose an inductor, which enables the
optimization of inductor size, efficiency and EMI.
The SSL5235TE can start up and operate in switching mode directly from line using an
external resistor without auxiliary supply. To provide a low-cost driver design, an
off-the-shelf inductor can be used, which provides flexibility in application design.
2. Features and benefits
Integrated MOSFET (5
/550
V)
Supports most available dimming solutions
Deep dimming level
Flicker-free dimming
Low component count ensuring a compact solution and small, single layer
Printed-Circuit Board (PCB) footprint
Excellent line regulation and load regulation and good LED output current accuracy
Efficient BCM operation with:
Minimal recovery losses in freewheel diode
Zero Current Switching (ZCS) and Valley switching for turn-on of switch
Minimum inductance value and size required
High efficiency (up to 88 %)
Ultra low IC current during operation (< 165
A)
Auto-recovery protections:
UnderVoltage LockOut (UVLO)
Cycle-by-cycle OverCurrent Protection (OCP)
Internal OverTemperature Protection (OTP)
Output OverVoltage Protection (OVP)
Output Short Protection (OSP)
Extended IC lifetime
NXP Semiconductors
SSL5235TE
Mains- dimmable buck-boost LED driver IC 5 Ohm/550 V
3. Applications
The SSL5235TE is intended for low-cost, non-isolated dimmable lighting applications
that work from single mains voltage.
4. Quick reference data
Table 1.
Symbol
V
CC
R
DSon
Quick reference data
Parameter
supply voltage
on-state
resistance
Conditions
operating range
I
I(DRAIN)
= 250 mA
T
j
= 25
C
T
j
= 125
C
I
I(DRAIN)
V
I(DRAIN)
[1]
[1]
Min
9.9
-
-
0.9
0.4
Typ
-
4.9
6.7
-
-
Max
16
-
-
+0.9
+550
Unit
V
A
V
input current on
pin DRAIN
input voltage on
pin DRAIN
duty cycle < 25 %
An internal clamp sets the supply voltage. The current into the VCC pin must not exceed the maximum I
VCC
value (see
Table 4).
5. Ordering information
Table 2.
Ordering information
Package
Name
SSL5235TE
HSO8
Description
plastic thermal enhanced small outline package; 8 leads; body width
3.9 mm; exposed die pad
Version
SOT786-1
Type number
SSL5235TE
All information provided in this document is subject to legal disclaimers.
© NXP Semiconductors N.V. 2015. All rights reserved.
Product data sheet
Rev. 1 — 13 March 2015
2 of 18
NXP Semiconductors
SSL5235TE
Mains- dimmable buck-boost LED driver IC 5 Ohm/550 V
6. Block diagram
Fig 1.
SSL5235TE block diagram
7. Pinning information
7.1 Pinning
Fig 2.
SSL5235TE pin configuration (HSO8 package)
SSL5235TE
All information provided in this document is subject to legal disclaimers.
© NXP Semiconductors N.V. 2015. All rights reserved.
Product data sheet
Rev. 1 — 13 March 2015
3 of 18
NXP Semiconductors
SSL5235TE
Mains- dimmable buck-boost LED driver IC 5 Ohm/550 V
7.2 Pin description
Table 3.
Symbol
GATE
ISNS
VCC
COMP
DIM
DEMOVP
GND
DRAIN
Pin description
Pin
1
2
3
4
5
6
7
8
Description
gate of internal switch
ground current sense input
supply voltage
loop compensation to provide stable response
dimming control input
input from LED output for demagnetization timing, valley detection,
and OVP
ground
drain of high-side internal MOSFET
8. Functional description
8.1 Converter operation
The SSL5235TE is a high-side switching on-time controlled BCM buck-boost converter.
Figure 3
shows the basic application diagram. To save IC supply current, an integrated
source-switch topology is used.
The converter operates at the boundary between Continuous Conduction Mode (CCM)
and Discontinuous Conduction Mode (DCM).
Figure 5
shows the waveforms.
When the internal switch is switched on at t0, the inductor current I
L
proportionally to V
in
builds up from zero during the source-switch on-time (t0 to t1). Energy is stored in inductor
L2. When the internal source-switch switches off at t1, I
L
flows through the freewheeling
diode D2 and the output capacitor C5. The inductor current drops proportionally to V
out
(t2
to t3). When I
L
reaches zero at t3, a new switching cycle is started after a short delay (t3 to
t00) from valley detection.
SSL5235TE
All information provided in this document is subject to legal disclaimers.
© NXP Semiconductors N.V. 2015. All rights reserved.
Product data sheet
Rev. 1 — 13 March 2015
4 of 18
NXP Semiconductors
SSL5235TE
Mains- dimmable buck-boost LED driver IC 5 Ohm/550 V
Fig 3.
SSL5235TE basic application diagram
8.2 On-time control
When measuring the inductor current I
L
using sense resistor R4, the on-time is regulated
so that the average ISNS voltage (V
intregd(AV)ISNS
) is regulated to 300 mV during the
off-time of the main switch. The average output current I
out
can be calculated with
Equation 1:
V
intregd
AV
ISNS
-
I
out
=
--------------------------------------
R4
(1)
8.3 Dimming control
When measuring the phase-cut mains voltage using the DIM pin, the DIM voltage
modulates the internal reference voltage. The dimmed output current I
O(dim)
can be
calculated with
Equation 2:
V
dim
itg
AV
ISNS
-
I
O
dim
=
----------------------------------------
R4
(2)
SSL5235TE
All information provided in this document is subject to legal disclaimers.
© NXP Semiconductors N.V. 2015. All rights reserved.
Product data sheet
Rev. 1 — 13 March 2015
5 of 18
京公网安备 11010802033920号
EEWORLD
