elm610da

ELM610DA 1.3A 36V PWM step down DC/DC converter
■General description
ELM610DA consists of step-down switching regulator with PWM control, reference voltage source, oscillation
circuit, error amplifier, internal PMOS, etc. ELM610DA provides low-ripple power, high efficiency, and
excellent transient characteristics; PWM control circuit is able to vary the duty ratio linearly from 0 up to 100%.
ELM610DA also contains error amplifier circuit as well as soft-start circuit that prevents overshoot at during
startup. Internal enable function, over current protect function and short circuit protect function will reduce the
operation frequency from 150kHz to 30kHz when overmuch current or short circuit occurs. Meanwhile, internal
compensation block is able to minimize the quantity of required external component. With internal P-channel
Power MOS, and externally connected coil, capacitor, and diode, ELM610DA is able to function as step-down
switching regulator. By the small package of SOP-8, ELM610DA is capable of working as ideal power supply
units for portable devices while providing outstanding features such as low current consumption. Since this
converter accommodates input voltage up to 36V, ELM610DA is also suitable for operations which adopt AC
adapter.
■Features
■Application
• Input voltage
: 5.5V to 36V
• Output voltage
: 0.8V to Vin
• Output current
: 1.3A
• Duty ratio
: 0% to 100%
• Constant frequency
: Typ.150kHz
• Soft-start
• Thermal shutdown protection
• Short circuit protection
• Built-in internal P-channel MOS
• Package
: SOP-8
•
•
•
•
•
•
•
•
•
PC motherboard
LCD monitor
Graphic card
DVD, blu-ray player
Telecom equipment
ADSL modem
Printer and other peripheral equipment
Microcomputer power supply
Network power supply
■Maximum absolute ratings
Parameter
VIN power supply voltage
Apply voltage to FB
Apply voltage to EN
Apply voltage to SW
Apply voltage to VC
Power dissipation
Operating temperature range
Storage temperature range
Symbol
Vin
Vfb
Ven
Vsw
Vc
Pd
Top
Tstg
Limit
-0.3 to +40
GND-0.3 to Vin
GND-0.3 to Vin+0.3
GND-0.3 to Vin+0.3
Vin-20 to Vin+0.3
300
-40 to +85
-65 to +150
Caution: Permanent damage to the device may occur when ratings above maximum absolute ones are used.
7- 1
Unit
V
V
V
V
V
mW
°C
°C
Rev.1.1
ELM610DA 1.3A 36V PWM step down DC/DC converter
■Selection guide
ELM610DA-N
Symbol
a
b
c
Package
Product version
Taping direction
D: SOP-8
A
N: Refer to PKG file
ELM610DA - N
↑↑ ↑
ab c
* Taping direction is one way.
■Pin configuration
SOP-8(TOP VIEW)
8
7
6
5
Pin No.
1
2
3
4
1
2
3
4
5, 6
7, 8
Pin name
Pin description
FB
Feedback(0.82V operation)
Enable / Disable
EN
H: Normal operation mode.(Step-down operation)
L: Shutdown mode.(All circuits deactivated)
Add an external capacitor to VIN.
VC
The voltage is set to Vin -7V
VIN
IC power supply
Switch. Connect external inductor/diode to here.
SW
Minimize trace area at this pin to reduce EMI.
GND
GND
■Standard circuit
ELM610DA
Vout=Vfb(1+R1/R2)
7- 2
Rev.1.1
ELM610DA 1.3A 36V PWM step down DC/DC converter
■Block diagram
Vin
VC
Oscillation circuit
SW
PWM
control circuit
Thermal
shutdown
protection
FB
Error
amplifier
Reference
voltage source
and soft start
EN
GND
■Electrical characteristics
Parameter
Input voltage
EN pin input voltage (*1)
Feedback voltage
Feedback bias current
Current limit
Quiescent current (switch off)
Current consumption
during power off
Voltage clamp
Oscillation frequency
Frequency of current limit
or short circuit protect
Vin=24V, Top=25°C, unless otherwise specified
Symbol
Condition
Min.
Typ.
Max. Unit
Vin
5.5
36.0
V
2.0
Venh Evaluate oscillation at SW pin
V
0.8
Venl Evaluate oscillation stop at SW pin
Vfb
Iout=0.1A
0.803 0.820 0.836
V
Ifb
Iout=0.1A
0.1
0.5
µA
Icl
2.0
A
Ignd EN ≥ Ven_h, Vfb=1V
1
2
mA
Ignd_off EN ≤ Ven_l
Vc
Fosc
No load
Foscl
1
10
µA
Vin-6
120
Vin-7
150
Vin-8
180
V
kHz
20
30
40
kHz
1
2
%
0.2
0.5
%
80
87
100
mΩ
%
50
μS
ΔVout
Vin=12V to 36V, Iout=0.2A
Vout
ΔVout
Load regulation
Iout=0.1 to 1.3A
Vout
Internal MOSFET Rdson
Rds(on) Vfb=0V, Iout=1A
Efficiency
η
Vin=24V, Vout=5V, Iout=1.3A
(*1) : Rise time and fall time of the EN pin use under the following conditions, please.
EN pin rise time & fall time
tr, tf
Ven=VenI to VenH
Line regulation
7- 3
Rev.1.1
ELM610DA 1.3A 36V PWM step down DC/DC converter
■Application notes
PWM Control
ELM610DA is DC/DC converter which consists pulse-width modulation (PWM) system. In converters of
ELM610DA, the pulse width varies according toe the load current, within the range from 0 to 100%. The ripple
voltage produced by switching can easily be removed through the filter since switching frequency remains constant; ELM610DA is capable of providing low-ripple power within broad ranges of input voltage and load current.
■Test circuits
■Marking
SOP-8
ELM
610DA
abc
Mark
ELM610DA
Content
Product name
abc
Assembly lot No.:
000 to 999 repeated
7- 4
Rev.1.1
ELM610DA 1.3A 36V PWM step down DC/DC converter
■Typical characteristics
V=1.8V : Cin=330µF, Cout=330µF, L=22µH, R1=5.1kΩ, R2=4.3kΩ, Top=25°C
•• Vout=1.8V
Vout-Vin
Iout=1mA
Vout (V)
2.0
100mA
1A
Vin=24V
1.6
1.2
10mA
0.8
4
8
40
20
0
0.1
1
10
100
Vin (V)
Iout (mA)
Vout-Iout
Vfb-Top
Vin=24V
1.8
1000
Vin=12V, Iout=0.1A
0.90
Vfb (V)
Vout (V)
Vin=6V
60
12 16 20 24 28 32 36
2
Vin=12V
80
0.4
0
EFFICIENCY-Iout
100
EFFICIENCY (%)
2.4
0.85
Vin=6V Vin=12V
0.80
1.6
0.1
1
10
100
Iout (mA)
-40
1000
20
40
Top (�)
60
Vin=12V, No load
80
Vin=12V, Iout=1mA�1A
Vout (V)
2.5
2
1
2
1.5
2
1
0
0
2
4
6
1
0
0
8 10 12 14 16 18 20
Time (ms)
7- 5
40
80
120
Time (ms)
160
Iout (A)
2
0
Ven (V)
Vout (V)
0
Load Transient Response
Start Response
3
-20
200
Rev.1.1
ELM610DA 1.3A 36V PWM step down DC/DC converter
•• Vout=3.3V
V=3.3V : Cin=330µF, Cout=330µF, L=22µH, R1=13.1kΩ, R2=4.3kΩ, Top=25°C
Vout-Vin
4.0
100mA
Iout=1mA
3.5
1A
EFFICIENCY (%)
Vout (V)
3.0
2.5
EFFICIENCY-Iout
100
10mA
2.0
1.5
1.0
Vin=24V
Vin=12V
80
Vin=6V
60
40
20
0.5
0
4
8
0
0.1
12 16 20 24 28 32 36
3.5
1
10
100
Vin (V)
Iout (mA)
Vout-Iout
Vfb-Top
1000
Vin=12V, Iout=0.1A
0.90
Vin=24V
Vfb (V)
3.3
3.2
Vin=5V
3.1
0.1
1
Vin=12V
10
100
Iout (mA)
0.85
0.80
-40
1000
Start Response
4
3
20
40
Top (�)
60
80
Vin=12V, Iout=1mA�1A
Vout (V)
3.5
2
1
3
2.5
2
0
2
1
1
Ven (V)
Vout (V)
0
Load Transient Response
Vin=12V, No load
3.5
-20
0
0
0
2
4
6
Iout (V)
Vout (V)
3.4
0 10 20 30 40 50 60 70 80 90 100
8 10 12 14 16 18 20
Time (ms)
Time (ms)
7- 6
Rev.1.1
ELM610DA 1.3A 36V PWM step down DC/DC converter
• Vout=5.0V
V=5.0V : Cin=330µF, Cout=330µF, L=22µH, R1=22kΩ, R2=4.3kΩ, Top=25°C
Vout-Vin
6.0
1A
100mA
Iout=1mA
EFFICIENCY (%)
Vout (V)
5.0
4.0
10mA
3.0
2.0
1.0
0
4
8
EFFICIENCY-Iout
100
Vin=24V
80
Vin=12V
Vin=6V
60
40
20
0
0.1
12 16 20 24 28 32 36
1
10
1000
Iout (mA)
Vin (V)
Vfb-Top
Vout-Iout
5.2
100
Vin=12V, Iout=0.1A
0.90
Vin=24V
Vfb (V)
Vout (V)
5
4.8
0.85
Vin=6V Vin=12V
0.80
4.6
0.1
1
10
100
Iout (mA)
-40
1000
Start Response
6
5
20
40
Top (�)
60
80
Vout (V)
4
3
2
Vin=12V, Iout=1mA�1A
5
4
3
1
0
2
1
1
0
0
0
2
4
6
8 10 12 14 16 18 20
Iout(A)
2
Ven (V)
Vout (V)
0
Load Transient Response
Vin=12V, No load
6
-20
0 10 20 30 40 50 60 70 80 90 100
Time (ms)
Time (mS)
7- 7
Rev.1.1
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