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부품번호 | A6210 기능 |
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기능 | 3A 2MHz Buck-Regulating LED Driver | ||
제조업체 | Allegro MicroSystems | ||
로고 | |||
전체 12 페이지수
A6210
3 A, 2 MHz Buck-Regulating LED Driver
Features and Benefits
▪ User-configurable on-time, achieving switching
frequencies up to 2.0 MHz
▪ Brightness control through PWM of DIS pin
▪ Minimal external components required
▪ No output capacitor required
▪ Wide input voltage range: 9 to 46 V
▪ Low 0.18 V sense voltage for higher efficiency
▪ Output Current: up to 3.0 A
▪ Low standby current <100 μA
▪ Thermal shutdown
▪ Supplied in a thermally-enhanced 4 mm QFN package
Applications:
▪ High brightness LEDs
▪ LED driver modules, power supplies and lamps, such as
MR16 and MR11
Package 16-contact QFN (suffix EU):
4 mm × 4 mm × 0.75 mm
Description
The A6210 is a buck regulator that uses valley current-mode
control. This control scheme allows very short switch on-times
to be achieved, making it ideal for applications that require
high switching frequencies combined with high input voltages
and low output LED span voltages.
Low system cost is accomplished through high switching
frequencies of up to 2.0 MHz, allowing smaller and lower value
inductors and capacitors. In addition, few external components
are required through high levels of integration. Optimal drive
circuits minimize switching losses.
The switching frequency is maintained constant, as the on-time
is modulated by the input voltage. This feed-forward control
ensures excellent line correction. The on-time is set by an
external resistor pulled-up to the input supply.
Internal housekeeping and bootstrap supplies are provided
which require the addition of only one small ceramic capacitor.A
top-off charge pump ensures correct operation at light loads.
Internal diagnostics provide comprehensive protection against
input undervoltages and overtemperatures.
The device package is a 16-contact, 4 mm × 4 mm, 0.75 mm
nominal overall height QFN, with exposed pad for enhanced
thermal dissipation. It is lead (Pb) free, with 100% matte tin
leadframe plating.
6210-DS, Rev. 2
VIN
24 V
R1
150 kΩ
C1
1.0 μF
Typical Application
VIN BOOT
LX
TON A 6210
ISEN
PWM or Switch
DIS
SGND
NC GND
C2
22 nF
L1
68 μH
D1
R2
390 mΩ
LED1
LED2
LED3
LED span voltage = 10.5 V
Average LED current = 500 mA
Peak to peak current = 60 mA
Switching frequency = 1.4 MHz
Efficiency = 90.5%
Suggested Parts
Name Description
C1 1 μF, 25V, X5R or X7R ceramic, 1210
C2 22 nF, 50V, X5R or X7R ceramic, 0805
D1 1 A, 30 V, Schottky diode
L1 68 μH, 1 A inductor
R1 180 kΩ, 1%, 0805
R2 390 mΩ, 1%, 0805
Manufacturer - Part Number
Taiyo Yuden, TDK
Taiyo Yuden - NR 6045T 680M
A6210
3 A, 2 MHz Buck-Regulating LED Driver
ELECTRICAL CHARACTERISTICS* valid at TJ = 25°C, VIN = 9 to 46 V, unless otherwise noted
Characteristic
Symbol
Conditions
Min.
General
VIN Quiescent Current
Current Sense Voltage
On-Time Tolerance
Minimum On-Time Period
Minimum Off-Time Period
Start-Up Time
IVINOFF
VSENSE
∆TON
Ton(min)
Toff(min)
tSTART
DIS = high, VIN = 46 V
Based on selected value
Using application circuit on page 1; time from
application of ¯D¯¯¯I¯S¯ (enable) to reaching target current
–
176
–15
–
–
–
Buck Switch On-Resistance
Input
RDS(on)
TJ = 25°C, ILOAD = 3 A
TJ = 125°C, ILOAD = 3 A
–
–
DIS Input Voltage Threshold
DIS Open-Circuit Voltage
DIS Input Current
Protection
VDIS
VDISOC
IIN
Device enabled
Device disabled
DIS = 0 V
–
2
–10
VIN Undervoltage Shutdown Threshold
VINUV Voltage rising
6.3
VIN Undervoltage Shutdown Hysteresis VINUV(hys)
0.7
Overtemperature Shutdown Threshold
TJTSD Temperature rising
–
Overtemperature Shutdown Hysteresis TJTSD(hys) Recovery = TJTSD – TJTSD(hys)
–
*Specifications over the junction temperature range of –40°C to 125°C are assured by design and characterization.
Typ.
–
183
–
50
–
15
350
550
–
–
–
–
–
165
15
Max. Units
100 μA
190 mV
15 %
60 ns
350 ns
– μs
– mΩ
– mΩ
1V
7V
–1 μA
7.5 V
1.1 V
– °C
– °C
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
4
4페이지 A6210
3 A, 2 MHz Buck-Regulating LED Driver
off-time of 350 ns. A minimum off-time is required to ensure the
bootstrap supply operates correctly. It can be shown that:
fSW
=
1–D
toff (min)
,
where toff is 350 ns maximum.
Therefore:
fSW
=
1 – 0.51
350 × 10–9
=
1.4
MHz
.
(8)
The ton resistor (R1) value can be found:
R1
=
VLED × 2.051 × 1010
fSW
12 × 2.051 × 1010
= 1.4 × 106
= 176 × 103
Choose R1 = 180 kΩ.
.
(9)
The inductor (L1) can now be found using the target LED ripple
current of 60 mA:
L1
=
(VIN – VLED) × D
I × fRIPPLE
SW
=
(24 – 12) × 0.51
60 × 10–3 × 1.4 × 106
= 72 × 10–6
.
(10)
Choose L1 = 68 μH.
The inductor current rating should exceed the average current
plus half of the ripple current. In addition, it is recommended that
a margin of at least 20% be allowed. In this example, the inductor
current rating, IL, should be:
IL ≥ 1.2 × (500 × 10–3 + 60 × 10–3 / 2) = 636 mA .
The valley control current is simply the average LED current
minus half the ripple current. Therefore:
I = I I 2VALLEY
av – RIPPLE
(11)
= 500 × 10–3 –
60 × 10–3
2
=
470 mA
.
The sense resistor (R3) value can be found:
VSENSE
R =3
IVALLEY
=
183 × 10–3
470 × 10–3
=
0.36
Choose R3 = 390 mΩ.
.
(12)
The ripple voltage developed across the sense resistor (R2) is
60 mA × 390 mΩ = 23 mV, which is greater than the minimum
required value of 20 mV.
Measured switching waveforms
From figure 3, it can be seen that the average current through
the LED string is 484 mA. This represents an error of 3.2% with
respect to the target current of 500 mA.
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
7
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구매 문의 | 일반 IC 문의 : 샘플 및 소량 구매 ----------------------------------------------------------------------- IGBT, TR 모듈, SCR 및 다이오드 모듈을 포함한 광범위한 전력 반도체를 판매합니다. 전력 반도체 전문업체 상호 : 아이지 인터내셔날 사이트 방문 : [ 홈페이지 ] [ 블로그 1 ] [ 블로그 2 ] |
부품번호 | 상세설명 및 기능 | 제조사 |
A6210 | 3A 2MHz Buck-Regulating LED Driver | Allegro MicroSystems |
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DataSheet.kr | 2020 | 연락처 | 링크모음 | 검색 | 사이트맵 |