E910.27A View Datasheet(PDF) - ELMOS Semiconductor AG
Part Name
Description
MFG CO.
'E910.27A' PDF : 50 Pages View PDF
- Preliminary -
E910.27A
7 Functional Description
7.1 Operation
7.1.1 Typical Application Circuit
VINPUT
CSM
ENPS
SMON
VSM
RFEX
RSEL
RLEV
AGND
POWER
SUPPLY
MUX
VR1
VR2
REFERENCE
VREF
VCMP
VSA
CCMP
PFM
For Sequencing
or RESET
PWGD
PWRGOOD
RPU
SGND CDLY WDI WEN
From VSM or VOUTPUT
CDLY
ERRPROC
VFB
ERR
SDLY
RFB1
RFB2
VSP
VILIM
E91027
CDRV
RSIN1
RSIN2
CIN
CDR
RS
HSDRV
OVTMP
UVLO
GND
PGND
SWD1
SWD2
DSW
VOUTPUT
LCK
COUT
Figure 7.1.1-1: Typical Application Circuit
7.1.2 Introduction
The E910.27 is a user friendly high voltage CMOS step-down DC-DC converter that provides an external
controllable output voltage. It features an internal 500mOhm (typically) P-channel MOS transistor switch for
high efficiency over a wide range of input/output voltages and currents. Moreover the converter can be ope-
rated over a very wide input supply range from 5V to 40V with typically 12µA shutdown and typically 170µA
stand by current, making them optimal for use in applications as automotive and industrial control.
Its sophisticated control scheme combines the advantages of pulse-skipping pulse-frequency modulation
(low supply current) and pulse-width modulation (high efficiency with heavy loads), providing high efficiency
over a wide input voltage and output current range. Operation up to 100% duty cycle allows the lowest possi-
ble dropout voltage, which allows a wider input voltage variation. Its small size, high switching frequency,
and low external parts count minimise the required circuit board area and component cost.
A reset signal is generated for a voltage at VFB below a level of VREF-15%. The watchdog circuit monitors a
connected controller. If there is no positive going edge at the watchdog input WDI within a fixed time, the
PWGD output is set low. The delay for power on reset and the maximum permitted watchdog pulse period
can be set externally with capacitor CDLY.
Figure 7.1.1-1 shows the E910.27 in a typical application circuit.
ELMOS Semiconductor AG
Specification 16 / 50
03SP0357E.00 05.09.2006
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