E522.31_16 Datasheet, PDF (12/20 Pages) ELMOS Semiconductor AG – CHANNEL SWITCHED MODE CONSTANT CURRENT CONTROLLER

1 CHANNEL SWITCHED MODE CONSTANT CURRENT CONTROLLER
PRODUCTION DATA - JUL 21, 2016
E522.31/33
5 Functional Description
5.1 General
The E522.3x family is a versatile high voltage controller
family for LED drivers. They can be configured for buck
from battery, buck-boost, SEPIC or boost topologies, ei-
ther to VIN or GND.
For further reduction of electromagnetic emission
E522.31/32 are running with spread spectrum local os-
cillator. The spread spectrum is only applied if there is
no input frequency at OSCIN.
This flexibility combined with the high supply voltage
of 55V, the very large output voltage range and the
possibility to drive high power LED arrays makes the
E522.3x family ideal for
The internal low-drop regulators VSM and V3V3 can be
used to supply external low-power components with a
total current consumption up to 15mA(E522.32/34)and
40mA(E522.31/33) at 5V (VSM) and 3.3V (V3V3) supply.
LED lighting applications
Automotive environment, e.g. headlight control
Residential and outdoor lighting applications
The E522.3x family consists of E522.31/33 for one LED
chain and E522.32/34 for two LED chains. In all two
channel family members the Switch Mode Power Sup-
plies are 180° out of phase for reduced EMI. Digital
PWM and analog dimming for each LED channel are in-
dependent and can be adjusted separately.
The internal oscillator can be configured for free-run-
ning mode with fixed frequency, controlled by a resistor
at the RT pin, or synchronized by an external clock input
at OSCIN (Slave mode in a Master-Slave configuration).
The LED controllers support PWM dimming for LED
brightness control without color change and analog
dimming for adjusting the LED initial current. The PWM
of E522.3x dimming allows a wide dimming ratio of
>1000:1 at PWM frequencies up to 400Hz.
5.2 Supply
The supply generates all necessary voltages to oper-
ate E522.3x from VIN. Furthermore supervision of V_VIN,
V_VSM, V_V3V3 and device temperature are performed.
The VSM low-drop voltage regulator provides 5V for pe-
ripheral structures and CGATE driver. It is controlled by
the ON pin and the internal temperature supervision.
For proper stabilization use typ. 1µF ceramic capaci-
tance (X7R recommended).
V3V3 voltage regulator is used to power most of the in-
ternal analog circuitry. It may also be used to drive ex-
ternal components, but in this case the total external
current provided by VSM and V3V3 must not exceed
40mA. Use 1µF ceramic capacitance (X7R) to stabilize
V3V3.
5.3 Oscillator
The internal oscillator defines the operation frequency
of the device, adjustable from 250 to 600kHz by an ex-
ternal resistor at pin RT. Any Frequency in this range can
be set by linear interpolation between the values given
in the table above ( R_RT=50kΩ*600kHz/frequency ). To
use the internal oscillator, solder OSCIN to AGND.
For synchronous operation to an external clock source,
a frequency can be applied to OSCIN.
In case of external clock it is necessary to apply a resis-
tor to RT with a value matching the synchronizing fre-
quency. Tolerance between frequency set by R_RT and f_OS-
CIN ^{is defined in RRT,OSCIN.}
Elmos Semiconductor AG reserves the right to change the detail specifications as may be required to permit improvements in the design of its products.
Elmos Semiconductor AG
Data Sheet
QM-No.: 25DS0085E.01
12/20