参数资料
| 型号： | ISL97652IRZ |
| 厂商： | Intersil |
| 文件页数： | 12/25页 |
| 文件大小： | 0K |
| 描述： | IC LCD SUPPLY HP 4CHN 48-QFN |
| 标准包装： | 43 |
| 应用： | LCD 电视机/监控器 |
| 电流 - 电源： | 500µA |
| 电源电压： | 8 V ~ 15 V |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 48-VFQFN 裸露焊盘 |
| 供应商设备封装： | 48-QFN（7x7） |
| 包装： | 管件 |
ISL97652
The boost converter uses a summing amplifier architecture
consisting of gm stages for voltage feedback, current
feedback and slope compensation. A comparator looks at
the peak inductor current cycle by cycle and terminates the
PWM cycle if the current limit is reached.
An external resistor divider is required to divide the output
voltage down to the nominal reference voltage. Current
drawn by the resistor network should be limited to maintain
the overall converter efficiency. The maximum value of the
resistor network is limited by the feedback input bias current
and the potential for noise being coupled into the feedback
pin. A resistor network in the order of 60k Ω is recommended.
The boost converter output voltage is determined by the
following equation:
higher frequency option is selected. The minimum boost
duty cycle of the ISL97652 is ~10% for 650kHz and ~20%
for 1.3MHz. When the operating duty cycle is lower than the
minimum duty cycle, the part will not switch in some cycles
randomly, which will cause some LX pulses to be skipped. In
this cas, LX pulses are not consistent any more, but the
output voltage (A VDD ) is still regulated by the ratio of R1 and
R2. Because some LX pulses are skipped, the ripple current
in the inductor will become bigger. Under the worst case, the
ripple current will be from 0 to the threshold of the current
limit. In turn, the bigger ripple current will increase the output
voltage ripple. Hence, it will need more output capacitors to
keep the output ripple at the same level. When the input
voltage equals, or is larger than, the output voltage, the
boost converter will stop switching. The boost converter is
V BOOST = --------------------- × V FB
R 1 + R 2
R 2
(EQ. 2)
not regulated any more, but the part will still be on and other
channels are still regulated.
I OMAX = ? I LMT – -------- ? × ---------
V O
The current through the MOSFET is limited to 2.8Apeak.
This restricts the maximum output current (average) based
on the following equation:
Δ I L V IN (EQ. 3)
? 2 ?
Where Δ IL is peak to peak inductor ripple current, and is set by:
Boost Converter Input Capacitor
An input capacitor is used to suppress the voltage ripple
injected into the boost converter. A ceramic capacitor with
capacitance larger than 10μF is recommended. The voltage
rating of input capacitor should be larger than the maximum
input voltage. Some capacitors are recommended in Table 2
for input capacitor.
Δ I L = --------- × -----
f S
V IN D
L
(EQ. 4)
TABLE 2. BOOST CONVERTER INPUT CAPACITOR
RECOMMENDATION
where f s is the switching frequency
The following table gives typical values (margins are
considered 10%, 3%, 20%, 10% and 15% on V IN , V O , L, f S
CAPACITOR
10μF/25V
10μF/25V
SIZE
1210
1210
VENDOR
TDK
Murata
PART NUMBER
C3225X7R1E106M
GRM32DR61E106K
and I OMAX ):
TABLE 1. MAXIMUM OUTPUT CURRENT CALCULATION
Boost Inductor
V IN (V)
12
12
12
V O (V)
15
15
18
L (μH)
6.8
6.8
6.8
f s (MHz)
0.65
1.3
0.65
I OMAX (mA)
1890
1955
1500
The boost inductor is a critical part which influences the
output voltage ripple, transient response, and efficiency.
Values of 3.3μH to 10μH should be selected to match the
internal slope compensation. The inductor must be able to
handle the following average and peak current:
I LAVG = -------------
I LPK = I LAVG + --------
12
8
8
8
8
18
15
15
18
18
6.8
6.8
6.8
6.8
6.8
1.3
0.65
1.3
0.65
1.3
1590
1200
1275
950
1050
I O
1 – D
Δ I L
2
Some inductors are recommended in Table 3.
(EQ. 5)
(EQ. 6)
TABLE 3. BOOST INDUCTOR RECOMMENDATION
When operating at the lower frequency option, 650kHz, the
DIMENSIONS
potential increase in ripple current in the inductor can be
INDUCTOR
(mm) VENDOR
PART NUMBER
avoided by increasing the inductor by the same factor. This
6.8μH/
7.3x6.8x3.2
TDK
RLF7030T-6R8N3R0
allows the slope compensation in the boost feedback to
3A PEAK
remain the same as the 1.3MHz case and this will maintain
stability of the converter over the widest operating range.
6.8μH/
2.9A PEAK
7.6X7.6X3.0 Sumida
CDR7D28MNNP-6R8NC
Operation at 650kHz allows boost operation down to lower
minimum duty cycles, where the output voltage required is
closer to the input voltage than can be achieved when the
5.2μH/
4.55A PEAK
10x10.1x3.8
Cooper
Bussmann
CD1-5R2
12
FN9287.1
November 2, 2007
相关PDF资料 |
PDF描述 |
|---|---|
| ISL97653AIRZ | IC LCD SUPPLY 5CHN 40-QFN |
| ISL97656IRTZ | IC REG BOOST ADJ 4A 10TDFN |
| ISL97701IRZ | IC REG BOOST ADJ 0.1A 10DFN |
| ISL97702IRZ-T7 | IC REG BOOST ADJ 0.13A DL 10DFN |
| ISL98012IUZ | IC REG BOOST ADJ 0.6A 10MSOP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| ISL97652IRZ-T | 功能描述:IC LCD SUPPLY 4CH DUAL AMP 48QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 电源管理 - 专用 系列:- 应用说明:Ultrasound Imaging Systems Application Note 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:37 系列:- 应用:医疗用超声波成像，声纳 电流 - 电源:- 电源电压:2.37 V ~ 6 V 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:56-WFQFN 裸露焊盘 供应商设备封装:56-TQFN-EP（8x8） 包装:管件 |
| ISL97652IRZ-TK | 功能描述:IC LCD SUPPLY 4CH DUAL AMP 48QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 电源管理 - 专用 系列:- 应用说明:Ultrasound Imaging Systems Application Note 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:37 系列:- 应用:医疗用超声波成像，声纳 电流 - 电源:- 电源电压:2.37 V ~ 6 V 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:56-WFQFN 裸露焊盘 供应商设备封装:56-TQFN-EP（8x8） 包装:管件 |
| ISL97653AIRZ | 功能描述:电流型 PWM 控制器 5-CH INTEGRTD LCD SUPPLY W/TEMP SENSOR RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14 |
| ISL97653AIRZ-T | 功能描述:电流型 PWM 控制器 5-CH INTEGRTD LCD SUPPLY W/TEMP SENSOR RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14 |
| ISL97653AIRZ-TK | 功能描述:电流型 PWM 控制器 5-CH INTEGRTD LCD SUPPLY W/TEMP SENSOR RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14 |
发布紧急采购，3分钟左右您将得到回复。