IC Phoenix
 
Home ›  LL2 > L4978-L4978D,2A STEP DOWN SWITCHING REGULATOR
L4978-L4978D Fast Delivery,Good Price
Part Number:
If you need More Quantity or Better Price,Welcom Any inquiry.
We available via phone +865332716050 Email
Partno Mfg Dc Qty AvailableDescript
L4978STMN/a10000avai2A STEP DOWN SWITCHING REGULATOR
L4978DSGS-THOMSONN/a10avai2A STEP DOWN SWITCHING REGULATOR


L4978 ,2A STEP DOWN SWITCHING REGULATORFeatures of this new generations of DC-DC con-DESCRIPTIONverter include pulse-by-pulse current limi ..
L4978D ,2A STEP DOWN SWITCHING REGULATORL4978®2A STEP DOWN SWITCHING REGULATORUP TO 2A STEP DOWN CONVERTEROPERATING INPUT VOLTAGE FROM 8V T ..
L4978D013TR ,2A STEP DOWN SWITCHING REGULATORELECTRICAL CHARACTERISTICS (T = 25°C, C = 2.7nF, Rosc = 20kΩ, V = 24V, unless other-j osc CCwise sp ..
L4979D ,LOW DROP VOLTAGE REGULATORL4979DL4979MDLOW DROP VOLTAGE REGULATORPRODUCT PREVIEW■ OPERATING DC SUPPLY VOLTAGE RANGE 6V TO 31V ..
L4979D013TR ,LOW DROP VOLTAGE REGULATORElectrical Characteristics (continued)Pin Symbol Parameter Test Condition Min. Typ. Max. UnitVOLTAG ..
L4979MD ,LOW DROP VOLTAGE REGULATORAbsolute Maximum Ratings" may cause permanent damage to the device. This is a stress rating only an ..
LBL293 , SmartLED® 0603 Hyper-Bright LED Lead (Pb) Free Product - RoHS Compliant
LBL293-L2N1-25-1 , SmartLED® 0603 Hyper-Bright LED Lead (Pb) Free Product - RoHS Compliant
LBL293-L2N1-25-1 , SmartLED® 0603 Hyper-Bright LED Lead (Pb) Free Product - RoHS Compliant
LBN04404 , SAW Filter Electrical Characteristic
LBN09010 , 90MHz SAW Filter 24MHz Bandwidth
LBR2012T100K , Wire-wound Chip Inductors (LB series)


L4978-L4978D
2A STEP DOWN SWITCHING REGULATOR
gerTpra'
2A STEP DOWN SWITCHING REGULATOR
UP TO 2A STEP DOWN CONVERTER
OPERATING INPUT VOLTAGE FROM 8V TO
n PRECISE 3.3V (i1%) INTERNAL REFER-
ENCE VOLTAGE
n OUTPUT VOLTAGE ADJUSTABLE FROM
3.3V TO 50V
n SWITCHING FREQUENCY ADJUSTABLE UP
TO 300KHZ
n VOLTAGE FEEDFORWARD
n ZERO LOAD CURRENT OPERATION
n INTERNAL CURRENT LIMITING (PULSE-BY-
PULSE AND HICCUP MODE)
.1 INHIBIT FOR ZERO CURRENT CONSUMP-
n PROTECTION AGAINST FEEDBACK DIS-
CONNECTION
n THERMAL SHUTDOWN
n SOFT START FUNCTION
DESCRIPTION
The L4978 is a step down monolithic power
switching regulator delivering 2A at a voltage be-
tween 3.3V and 50V (selected by a simple exter-
nal divider). Realized in BCD mixed technology,
the device uses an internal power D-MOS transis-
tor (with a typical Rdson of 0.259) to obtain very
high eNcency and high switching speed.
TYPICAL APPLICATION CIRCUIT
'iiiiiiii)ti;;;;;i)r,
Minidip SO16W
ORDERING NUMBERS: L4978 (Minidip)
L4978D (SO16)
A switching frequency up to 300KHz is achiev-
able (the maximum power dissipation of the pack-
ages must be observed).
A wide input voltage range between 8V to 55V
and output voltages regulated from 3.3V to 50V
cover the majority of today's applications.
Features of this new generations of DC-DC con-
verter include pulse-by-pulse current limit, hiccup
mode for short circuit protection, voltage feedfor-
ward regulation, soft-start, protection against
feedback loop disconnection, inhibit for zero cur-
rent consumption and thermal shutdown.
The device is available in plastic dual in line,
MINIDIP 8 for standard assembly, and SO16W
for SMD assembly.
Vi=8Vto 55V
7 1 6 LI V =3.3V/2A
220 A A A 126pH C)
63V " I I (77120)
Ce '==,
R2 100nF --
9.1K Ca
T 22nF
DQBIN83 TA
October 2001
BLOCK DIAGRAM
THERMAL - VOLTAGES I
SHUTDOWN MONITOR
I CBOOT
CHARGE
2 INTERNAL INTERNAL
SS_INH _ INHIBIT - SOFTSTART o- REFERENCE - SUPPLY Tfl, l
3.3V .
COMP 7 - - e
FB PWM R
o - CBOOT
3.3V l" S :} CHARGE
DRIVE AT LIGHT
OSCILLATOR I
l 3 l 4
OSC GND OUT D97iN594
PIN CONNECTIONS
N.C. CI: 1 16 D N.C.
GND U: 2 15 CIC) N.C.
V INH 14 FB
GND E 1 8 Cl F B ss, g 3 g
OSC 4 13 COMP
SS_INH E 2 7 Cl COMP OUT CE 5 12 D BOOT
OSC l: 3 6 Cl BOOT
OUT I: 4 5 Cl VCC OUT Cl: 6 11 CIC) VCC
N.C. CE 7 10 ID NO.
D97IN595 N.C. UE 8 9 CIC) NC.
D97IN596
Minidip SO16W
PIN FUNCTIONS
DIP SO (*) Name Function
1 2 GND Ground
2 3 SS_INH A logic signal (active low) disables the device (sleep mode operation).
A capacitor connected between this pin and ground determines the soit start time.
When this pin is grounded disables the device (driven by open collector/drain).
3 4 OSC An external resistor connected between the unregulated input voltage and this pin and
a capacitor connected from this pin to ground fix the switching frequency. (Line feed
forward is automatically obtained)
4 5, 6 OUT Stepdown regulator output
5 11 Vcc Unregulated DC input voltage
6 12 BOOT A capacitor connected between this pin and OUT allows to drive the internal DMOS
Transistors
7 13 COMP E/A output to be used for frequency compensation
8 14 FB Stepdown feedback input. Connecting directly to this pin results in an output voltage of
3.3V. An external resistive divider is required for higher output voltages.
(*) Pins 1, 7, 8, 9, 10, 15 and 16 are not internally, electrically connected to the die.
2/12 £77
ic,good price


TEL:86-533-2716050      FAX:86-533-2716790
   

©2020 IC PHOENIX CO.,LIMITED