ELANT EL7562CU Datasheet
(3.3V,
EL7562C - Preliminary
Monolithic 2 Amp DC:DC Step-down Regulator
EL7562C - Preliminary
Features
• Integrated synchronous MOSFETs
and current mode controller
• 2A continuous output current
• Up to 95% efficiency
• 4.5V to 5.5V input voltage
• Adjustable output from 1V to 3.8V
• Cycle-by-cycle current limit
• Precision reference
• ±0.5% load and line regulation
• Adjustable switching frequency to
1MHz
• Oscillator synchronization
possible
• Internal soft start
• Over temperature protection
• Under voltage lockout
• 16-pin QSOP package
Applications
• DSP, CPU Core and IO Supplies
• Logic/Bus Supplies
• Portable Equipment
• DC:DC Converter Modules
• GTL + Bus Power Supply
Ordering Information
Part No Package Tape & Reel Outline #
EL7562CU 16-Pin QSOP - MDP0040
General Description
The EL7562C is an integrated, synchronous step-down regulator with
output voltage adjustable from 1.0V to 3.8V. It is capable of delivering
2A continuous current at up to 95% efficiency. The EL7562C operates
at a constant frequency pulse width modulation (PWM) mode, making
external synchronization possible. Patented on-chip resistorless current sensing enables current mode control, which provides cycle-bycycle current limiting, over-current protection, and excellent step load
response. The EL7562C is available in a fused-lead 16-pin QSOP
package. With proper external components, the whole converter fits
into a less than 0.5 in2 area. The minimal external components and
small size make this EL7562C ideal for desktop and portable
applications.
The EL7562C is specified for operation over the -40°C to +85°C temperature range.
Typical Application Diagram
V
5.5V)
1
C3C
4
0.1µF 270pF
R
3
39Ω
C1C
2
100µF 0.1µF
IN
SGND
2
COSC
3
VDD
4
PGND
5
PGND
6
VIN
7
VIN
8 9
EN
PGND
VREF
VDRV
VHI
PGND
16
15
14
FB
13
12
LX
11
LX
10
C
0.1µF
5
R
1
1kΩ
C
6
0.1µF
R
2.37k
L
4.7µF
2
1
C
7
100µF
2A)
V
O
October 25, 2001
Manufactured under U.S. Patent No. 57,323,974
Note: All information contained in this data sheet has been carefully checked and is believed to be accurate as of the date of publication; however, this data sheet cannot be a “controlled document”. Current revisions, if any, to these
specifications are maintained at the factory and are available upon your request. We recommend checking the revision level before finalization of your design documentation.
© 2001 Elantec Semiconductor, Inc.
EL7562C - Preliminary
Monolithic 2 Amp DC:DC Step-down Regulator
Absolute Maximum Ratings (T
Supply Voltage between VIN or VDD and GND +6.5V
VLX Voltage VIN +0.3V
Input Voltage GND -0.3V, VDD +0.3V
VHI Voltage GND -0.3V, V
EL7562C - Preliminary
= 25°C)
A
LX
Storage Temperature -65°C to +150°C
Operating Ambient Temperature -40°C to +85°C
Operating Junction Temperature +135°C
+6V
Important Note:
All parameters having Min/Max specifications are guaranteed. Typ values are for information purposes only. Unless otherwise noted, all tests are at the
specified temperature and are pulsed tests, therefore: TJ = TC = TA.
DC Characteristics
V
= V
= 5V, TA = TJ = 25°C, C
DD
IN
Parameter Description Conditions Min Typ Max Unit
V
REF
V
REFTC
V
REFLOAD
V
RAMP
I
OSC_CHG
I
OSC_DIS
I
VDD+VDRVVDD+VDRV
I
VDD_OFF
V
DD_OFF
V
DD_ON
T
OT
T
HYS
I
LEAK
I
LMAX
R
DSON
R
DSONTC
V
FB
V
FB_LINE
V
FB_LOAD
V
FB_TC
I
FB
V
EN_HI
V
EN_LO
I
EN
Reference Accuracy 1.24 1.26 1.28 V
Reference Temperature Coefficient 50 ppm/°C
Reference Load Regulation 0 < I
Oscillator Ramp Amplitude 1.15 V
Oscillator Charge Current 0.1V < V
Oscillator Discharge Current 0.1V < V
Supply Current VEN = 4V, F
V
Standby Current EN = 0 1 1.5 mA
DD
VDD for Shutdown 3.5 3.9 V
VDD for Startup 3.95 4.35 V
Over Temperature Threshold 135 °C
Over Temperature Hysteresis 20 °C
Internal FET Leakage Current EN = 0, LX = 5V (low FET), LX = 0V (high FET) 10 µA
Peak Current Limit 3 A
FET On Resistance Wafer level test only 60 120 mΩ
R
Tempco 0.2 mΩ/°C
DSON
Output Initial Accuracy I
Output Line Regulation V
Output Load Regulation 0.1A < I
Output Temperature Stability -40°C < TA < 85°C, I
Feedback Input Pull Up Current V
EN Input High Level 3.2 4 V
EN Input Low Level 1 V
Enable Pull Up Current VEN = 0 -4 -2.5 µA
= 1.2nF, unless otherwise specified.
OSC
LOAD
IN
FB
< 50µA -1 %
REF
< 1.25V 200 µA
OSC
< 1.25V 8 mA
OSC
= 120kHz 2 3.5 5 mA
OSC
= 0A 0.960 0.975 0.99 V
= 5V, ∆V
= 10%, I
IN
< 1A 0.5 %
LOAD
= 0A 0.5 %
LOAD
= 0.5A ±1 %
LOAD
= 0V 100 200 nA
Closed Loop AC Electrical Characteristics
VS = V
= 5V, TA = TJ = 25°C, C
IN
Parameter Description Conditions Min Typ Max Unit
F
OSC
t
SYNC
M
t
BRM
t
LEB
D
SS
MAX
Oscillator Initial Accuracy 105 117 130 kHz
Minimum Oscillator Sync Width 25 ns
Soft Start Slope 0.5 V/ms
FET Break Before Make Delay 15 ns
High Side FET Minimum On Time 150 ns
Maximum Duty Cycle 95 %
= 1.2nF, unless otherwise specified.
OSC
2
EL7562C - Preliminary
Monolithic 2 Amp DC:DC Step-down Regulator
Pin Descriptions
Pin Number Pin Name Pin Function
1 SGND Control circuit negative supply.
2 COSC Oscillator timing capacitor. FOSC can be approximated by: FOSC (kHz) = 0.1843/COSC, COSC in µF.
3 VDD Control circuit positive supply.
4 PGND Ground return of the regulator. Connected to the source of the low-side synchronous NMOS power FET.
5 PGND Ground return of the regulator. Connected to the source of the low-side synchronous NMOS power FET.
6 VIN Power supply input of the regulator. Connected to the drain of the high-side NMOS power FET.
7 VIN Power supply input of the regulator. Connected to the drain of the high-side NMOS power FET.
8 EN Chip Enable, active high. A 2µA internal pull-up current enables the device if the pin is left open.
9 PGND Ground return of the regulator.
10 VHI Positive supply of the high-side driver.
11 LX Inductor drive pin. High current digital output whose average voltage equals the regulator output voltage.
12 LX Inductor drive pin. High current digital output whose average voltage equals the regulator output voltage.
13 VDRV Positive supply of the low-side driver and input voltage for the high-side boot strap.
14 FB Voltage feedback input. Connected to an external resistor divider between VOUT and GND. A 125nA pull-up current
15 VREF Bandgap reference bypass capacitor. Typically 0.1µF to GND.
16 PGND Ground return of the regulator.
forces VOUT to VS in the event that FB is floating.
EL7562C - Preliminary
3
Loading...