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부품번호 | ACE716E 기능 |
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기능 | Variable Frequency Step-up DC/DC Converter | ||
제조업체 | ACE Technology | ||
로고 | |||
ACE716E
Max 38V, Variable Frequency Step-up DC/DC Converter
Description
The ACE716E is a high efficiency step-up converter with an internally integrated 40V power MOSEFT.
It runs with an optimal 0.8MHz frequency that enables use of small external components while still
providing best efficiencies. It has an internal current limit as high as 1A, and it can drive up to 10 LEDs at
50mA output current. The incorporated 25-100KHz true PWM-Dimming feature by EN pin can be used to
digitally program the LED current. For maximum protection, the ACE716E has an internal OVP protection
at 38V to prevent the chip from damages when the LED string is not connected to the output.
ACE716E is available in a space-saving SOT23-6 package.
Features
• Up to 90% Efficiency (6 LEDs)
• Drive up to 10 LEDs with 50mA
• Drive up to 40 LEDs in total
• 38V OVP protection
• True PWM Brightness Control
• 200mV Feedback Voltage
• 1A current limit
• SOT23-6 Package
Application
• Cellphone and Smartphone
• MID or Tablet PC
• TFT-bias for LCD screen
• Power for OLED
• LED torch
• Satellite Set Top Box
Absolute Maximum Rating
Parameter
Value
SW Voltage
-0.3V~38V
All Other PIN Voltages
-0.3V~6.5V
SW to ground current
Internally limited
Operating Temperature Range
-40℃~85℃
Storage Temperature Range
-55℃~150℃
Thermal Resistance (Θjc)
SOT23-6
ΘJA ΘJC
100 50 ℃/W
Note: Exceed these limits to damage to the device. Exposure to absolute maximum rating conditions may affect device reliability.
VER 1.2 1
Typical Application
ACE716E
Max 38V, Variable Frequency Step-up DC/DC Converter
USB Power Application Circuit
VOUT = 0.2x(1+R1/R2)
Note: The Pin6, Vin Pin of ACE716E
is connected to 5V, not the battery input.
Circuit lefthand is only for output than 5.5V!
Please connect Pin6 to input if output is to
Be larger than 5.5V.
VER 1.1
4
4페이지 ACE716E
Max 38V, Variable Frequency Step-up DC/DC Converter
FUNCTIONAL DECRIPTIONS
The ACE716E is a high efficiency boost LED driver with a small package size. The device is ideal for
driving 2-25LEDs for backlight application in smartphone and 7-inch tablet PC. The device integrates a
38V/1A switch FET and operates in pulse width modulation (PWM) with a 0.8MHz fixed switching
frequency. For operation details, please check the block diagram in the “Block Diagram” chapter. The duty
cycle of the converter is set by the error amplifier output and the current signal applied to the PWM
control comparator. The feedback loop regulates the FB pin to a low reference voltage (200mV typical),
reducing the power dissipation in the current sense resistor.
Output Open Circuit Protection
Output open circuit protection circuitry prevents IC damage as the result of output open circuit (e.g. LED
string absence). The ACE716E monitors the voltage at the SW pin and FB pin during each switching
cycle. The circuitry turns off the switch FET and shuts down the IC when both of the following conditions
persist for 8 switching clock cycles: (1) the SW voltage exceeds the VOVP threshold, which is 38V and (2)
the FB voltage is less than half of regulation voltage. As a result, the output voltage falls to the level of the
input supply. The device remains in shutdown mode until it is enabled by toggling the EN pin logic. The
output voltage plus the 200mV reference voltage cannot exceed the minimum OVP threshold or OUTPUT
VOLTAGE + 200 mV ≤ VOVP(MIN).
Shutdown
The ACE716E enters shutdown mode when the EN voltage is logic low for more than 3ms. During
shutdown, the input supply current for the device is less than 1μA (max). Although the internal FET does
not switch in shutdown, there is still a DC current path between the input and the output through the
inductor and Schottky diode.
For LED driving application, the minimum forward voltage of the LED array must exceed the maximum
input voltage to ensure that the LEDs remain off in shutdown. However, in the typical application with two
or more LEDs, the forward voltage is large enough to reverse bias the Schottky and keep leakage current
low.
LED Driving Current Setting
The FB voltage is regulated by a low 0.2V reference voltage. The LED current is set externally using a
current-sense resistor in series with the LED string. The value of the RSET is calculated using Equation
1.2:
ILED =0.2/RSET
(1.2)
Where
ILED = output current of LEDs, RSET = current sense resistor
The output current tolerance depends on the FB accuracy and the current sensor resistor accuracy.
PWM Dimming Control or Output Voltage Programming
When the CTRL pin is constantly high, the FB voltage is regulated to 200mV typically. However, the EN
pin allows a PWM signal to reduce this regulation voltage; therefore, it achieves LED brightness dimming
or output voltage programming (only to make output voltage lower). The relationship between the duty
cycle and FB voltage is given by Equation 2.
VER 1.1
7
7페이지 | |||
구 성 | 총 10 페이지수 | ||
다운로드 | [ ACE716E.PDF 데이터시트 ] |
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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 |
ACE716E | Variable Frequency Step-up DC/DC Converter | ACE Technology |
DataSheet.kr | 2020 | 연락처 | 링크모음 | 검색 | 사이트맵 |