|
|
|
부품번호 | TS1518 기능 |
|
|
기능 | White LED Driver | ||
제조업체 | Taiwan Semiconductor Company | ||
로고 | |||
전체 7 페이지수
TS1518
Step-Up DC-DC Converter, Whwwitwe.DaLtaEShDeet4DU.croivmer
SOT-25
Pin Definition:
1. SW
2. Ground
3. Feedback
4. CTRL
5. Input
General Description
The TS1518 is a step-up DC-DC converter; operates as current source to drive up to 6 white LEDs(VIN at 3.0V) or 8
LEDs(VIN at 3.5V) or 9 LEDs(VIN at 3.5V) in series. Series connecting of the LEDs provides identical LED currents
resulting in uniform brightness and eliminating the need for ballast resistors. The light intensity of these LEDs is
proportional to the current passing through them. The TS1518 switches at a fixed frequency of ~930KHz, allowing the
use of tiny, low profile inductors and capacitors to minimize footprint and cost in space consideration applications for
cellular phone backlighting or other hand held equipment. The TS1518 can drive up to 9 white LEDs from a single Li-
Ion battery. The wide input voltage range from 2.7V to 7V is ideal for portable with higher conversion efficiency. To
control LED brightness, the LED current can be pulsed by applying a PWM (pulse width modulated) signal with a
frequency range of 100Hz to 1KHz to the CTRL pin.
TS1518 has integrated Latched Over Voltage Protection that prevents damage to the device in case of a high
impedance output due to faulty LED or open circuit caused by abnormal conditions.
Features
● Built-in Internal Switch
● PWM dimming control 100Hz to 1KHz
● Analog dimming control
● 2.7V to 7V input range
● <1uA shutdown current
● Internal Soft Start
● Drives up to 9 White LEDs (VIN at 3.5V)
● Over Voltage Protection 34V
● 100mV Low Reference Voltage
Application
● Cellular Phones
● Digital Still Cameras
● Portable Electronics
● LCD Display Module
● White LED Backlighting
● PDAs, GPS terminals
Ordering Information
Part No.
TS1518CX5 RF
Package
SOT-25
Packing
3Kpcs / 7” Reel
Typical Application Circuit
1/7 Version: B07
TS1518
Step-Up DC-DC Converter, Whwwitwe.DaLtaEShDeet4DU.croivmer
Application Information
Operation
The TS1518 uses a constant frequency, current mode control scheme to regulate the output LED current. Its operation
can be understood by referring to the block diagram in Figure 3. At the start of each oscillator cycle, a voltage
proportional to the switch current is added to a ramp output and the resulting sum is fed into the positive terminal of the
PWM comparator (comparator-1). When this voltage exceeds the level of the comparator negative input, the peak
current has been reached, and the SR latch (in Control Logic) is reset and turns off the power switch. The voltage at
the negative input of the comparator comes from the output of the error amplifier. The error amplifier sets the correct
peak current level to keep the output in regulation. If the error amplifier’s output increases, more current is delivered to
the output; if it decreases, less current is delivered.
Soft Start and Current Limit
The internal soft start circuit minimizes the inrush current during turning on TS1518. The maximum switch current is
limited to about 450 mA by the chip.
Open Circuit Protection
The TS1518 has an internal latched off open-circuit protection circuit. When the LEDs are disconnected from the circuit
or fail open, the TS1518 will shutdown automatically until input condition changes to bring it out of the shutdown mode.
Inductor Selection
A 22uH inductor is recommended for most applications to drive more than 5 LEDs. Although small size and high
efficiency are major concerns, the inductor should have low core losses at 1MHz and low DCR (copper wire
resistance).
Diode Selection
To maintain high efficiency, the average current rating of the Schottky diode should be large than the peak inductor
current, IPK. Schottky diode with a low forward drop and fast switching speeds are ideal for increase efficiency in
portable application. Choose a reverse breakdown of the Schottky diode large than the output voltage.
Capacitor Selection
Choose low ESR capacitors for the output to minimize output voltage ripple. Multilayer capacitors are a good choice for
this as well. A 1uF capacitor is sufficient for 2~6 LEDs, 2.2uF is for 7~8 LEDs and 4.7uF is for 9 LEDs applications.
For additional bypassing, a 100nF ceramic capacitor can be used to shunt high frequency ripple on the input.
The input bypass capacitor Cin, as shown in Figure 1, must be placed close to the IC. This will reduce copper trace
resistance which affects input voltage ripple of the IC. For additional input voltage filtering, a 100nF bypass capacitor
can be placed in parallel with Cin to shunt any high frequency noise to ground. The output capacitor, Cout, should also
be placed close to the IC. Any copper trace connections for the Cout capacitor can increase the series resistance,
which directly effect output voltage ripple.
The feedback network, resister R2 should be kept close to the FB pin to minimize copper trace connections that can
inject noise into the system. The ground connection for the feedback resistor network should connect directly to an
analog ground plane. The analog ground plane should tie directly to the GND pin. If no analog ground plane is
available, the ground connection for the feedback network should tie directly to the GND pin. Trace connections made
to the inductor and Schottky diode should be minimized to reduce power dissipation and increase overall efficiency.
4/7 Version: B07
4페이지 TS1518
Step-Up DC-DC Converter, Whwwitwe.DaLtaEShDeet4DU.croivmer
Notice
Specifications of the products displayed herein are subject to change without notice. TSC or anyone on its behalf,
assumes no responsibility or liability for any errors or inaccuracies.
Information contained herein is intended to provide a product description only. No license, express or implied, to any
intellectual property rights is granted by this document. Except as provided in TSC’s terms and conditions of sale for
such products, TSC assumes no liability whatsoever, and disclaims any express or implied warranty, relating to sale
and/or use of TSC products including liability or warranties relating to fitness for a particular purpose, merchantability,
or infringement of any patent, copyright, or other intellectual property right.
The products shown herein are not designed for use in medical, life-saving, or life-sustaining applications. Customers
using or selling these products for use in such applications do so at their own risk and agree to fully indemnify TSC for
any damages resulting from such improper use or sale.
7/7 Version: B07
7페이지 | |||
구 성 | 총 7 페이지수 | ||
다운로드 | [ TS1518.PDF 데이터시트 ] |
당사 플랫폼은 키워드, 제품 이름 또는 부품 번호를 사용하여 검색할 수 있는 |
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 |
TS151 | GLASS PASSIVATED JUNCTION PLASTIC RECTIFIER | TRSYS |
TS1510 | GLASS PASSIVATED JUNCTION PLASTIC RECTIFIER | TRSYS |
DataSheet.kr | 2020 | 연락처 | 링크모음 | 검색 | 사이트맵 |