收藏本站
BD6142AMUV
Datasheet
● Coil selection
The DC/DC is designed by more than 4.7μH. When L value sets to a lower value, it is possibility that the specific
sub-harmonic oscillation of current mode DC / DC will be happened. Please do not let L value to 3.3μH or below.
And, L value increases, the phase margin of DC / DC becomes to zero. Please enlarge the output capacitor value when you
increase L value. Please select lower DC resistance (DCR) type, efficiency still relies on the DCR of Inductor.
Please estimate Peak Current of Coil. Peak current can be calculated as following.
Peak Current calculation
<The estimate of the current value which need for the normal operation>
As over current detector of this IC is detected the peak current, it have to estimate peak current to flow to the coil by
operating condition.
In case of, - Supply voltage of coil = V In
- Inductance value of coil = L
- Switching frequency = fsw (Min=1.0MHz, Typ = 1.25MHz, Max = 1.5MHz)
- Output voltage = VOUT - Total LED current = I LED
- Average current of coil = Iave - Peak current of coil = Ipeak
- Cycle of Switching = T - Efficiency = eff (Please set up having margin)
- ON time of switching transistor = Ton - ON Duty = D
CCM: Ipeak = (V In / L) × (1 / fsw) × (1-( V In / VOUT)), DCM: Ipeak = (V In / L) × Ton
Iave=( VOUT × IOUT / V In ) / eff
Ton=(Iave × (1- V In / VOUT) × (1/fsw) × (L/ V In ) × 2) 1/2
Each current is calculated.
As peak current varies according to whether there is the direct current superposed, the next is decided.
CCM: (1- V In / VOUT) × (1/fsw) < Ton ? peak current = Ipeak /2 + Iave
DCM: (1- V In / VOUT) × (1/fsw) > Ton ? peak current = V In / L × Ton
(Example 1)
In case of, V In = 7.0V, L = 10μH, fsw = 1.2MHz, VOUT = 32V, I LED = 120mA, Efficiency = 88%
Iave = (32 × 120m / 7) / 88% = 0.62A
Ton = (0.62 × (1 - 7 / 32) × (1 / 1.2M) × (10μ / 7) × 2) 1/2 = 1.07μs
(1- V In / VOUT) × (1 / fsw) = 0.65μs < Ton(1.07μs) CCM
Ipeak = (7 / 10μ) × (1 / 1.2M) × (1 - (7 / 32)) = 0.46A
Peak current = 0.46A / 2 + 0.62A = 0.85A
(Example 2)
In case of, V In = 16.0V, L = 10μH, fsw = 1.2MHz, VOUT = 32V, I LED = 120mA, Efficiency = 88%
Iave = (32 × 120m / 16.0) / 88% = 0.27A
Ton = (0.27 × (1-16 / 32) × (1 / 1.2M) × (10μ / 16) × 2) 1/2 = 0.37μs
(1- V In / VOUT) × (1 / fsw)=0.41μs > Ton(0.37μs) DCM
Ipeak = V In / L x Ton = 16 / 10μ x 0.37μs = 0.59A
Peak current = 0.59A
*When too large current is set, output overshoot is caused, be careful enough because it is led to break down of the IC in
case of the worst.
DCM/CCM calculation
Discontinuous Condition Mode (DCM) and Continuous Condition Mode (CCM) are calculated as following.
CCM: L > VOUT × D × (1 - D) 2 × T / (2 × I LED )
DCM: L < VOUT × D × (1 - D) 2 × T / (2 × I LED )
*D = 1- V In / VOUT
(Example 1)
In case of, V In = 7.0V, L = 10μH, fsw = 1.2MHz, VOUT = 32V, I LED = 120mA
VOUT × D × (1 - D) 2 × T / (2 × I LED ) = 32 × (1 – 7 / 32) × (7 / 32) 2 × 1/(1.2 × 10 6 ) / (2 × 0.12) = 4.15μ < L(10μH)
? CCM
(Example 2)
In case of, V In = 12.0V, L = 10μH, fsw = 1.2MHz, VOUT = 32V, I LED = 60mA
VOUT × D × (1 - D) 2 × T / (2 × I LED ) = 32 × (1 – 12 / 32) × (12 / 32) 2 × 1/(1.2 × 10 6 ) / (2 × 0.06) = 19.5μ > L(10μH)
? DCM
www.rohm.com
? 2011 ROHM Co., Ltd. All rights reserved.
TSZ22111 ? 15 ? 001
19/30
TSZ02201-0G3G0C400340-1-2
03.Dec.2012 Rev.001
发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

*型号 *数量 厂商 批号 封装
添加更多采购

我的联系方式

*
*
*
相关PDF资料
BD6581GU-E2 IC LED DVR WHT BCKLGHT VCSP85H2
BD6583MUV-AE2 IC LED DRIVER WHIT BCKLGT 24VQFN
BD6586MUV-E2 IC LED DRVR WHITE BCKLGT 24-VQFN
BD6592MUV-E2 IC LED DRVR WHITE BCKLGT 24-VQFN
BD7844AEFV-E2 IC LED DISPLAY DVR 5V 28-HTSSOP
BD8105FV-E2 IC LED DVR SERIAL PAR 20-SSOP
BD8112EFV-ME2 IC LED DRIVER 24-VSSOP
BD8119FM-ME2 IC WHITE LED DVR PWM 28-HSOP
相关代理商/技术参数
BD615 制造商:INFINEON 制造商全称:Infineon Technologies AG 功能描述:PNP SILICON EPIBASE TRANSISTORS
BD6150CS 制造商:PANJIT 制造商全称:Pan Jit International Inc. 功能描述:SURFACE MOUNT SCHOTTKY BARRIER RECTIFIERS
BD6150CT 制造商:PANJIT 制造商全称:Pan Jit International Inc. 功能描述:SURFACE MOUNT SCHOTTKY BARRIER RECTIFIERS
BD6150MUV 制造商:ROHM 制造商全称:Rohm 功能描述:White Backlight LED Driver for Medium to Large LCD Panels (Switching Regulator Type)
BD6150MUV_11 制造商:ROHM 制造商全称:Rohm 功能描述:White Backlight LED Driver for Medium to Large LCD Panels (Switching Regulator Type)
BD6150MUV-E2 制造商:ROHM Semiconductor 功能描述:CONV DC-DC SINGLE STEP UP 4.2V TO 26V 24-PIN VQFN EP T/R - Tape and Reel 制造商:ROHM Semiconductor 功能描述:IC WHITE LED DVR BKLT 24-VQFN 制造商:ROHM Semiconductor 功能描述:CONV DCDC SNGL STPDN 2V-26V 24PIN 制造商:ROHM Semiconductor 功能描述:White Backlight LED Driver,106 LED,30mA
BD6155FVM 制造商:ROHM 制造商全称:Rohm 功能描述:DC/DC converter for LCD back light
BD6155FVM-E2 功能描述:IC LED DRIVR WHITE BCKLGT 8-MSOP RoHS:是 类别:集成电路 (IC) >> PMIC - LED 驱动器 系列:- 标准包装:6,000 系列:- 恒定电流:- 恒定电压:- 拓扑:开路漏极，PWM 输出数:4 内部驱动器:是 类型 - 主要:LED 闪烁器 类型 - 次要:- 频率:400kHz 电源电压:2.3 V ~ 5.5 V 输出电压:- 安装类型:表面贴装 封装/外壳:8-VFDFN 裸露焊盘 供应商设备封装:8-HVSON 包装:带卷 (TR) 工作温度:-40°C ~ 85°C 其它名称:935286881118PCA9553TK/02-TPCA9553TK/02-T-ND