参数资料
| 型号： | SC4524CSETRT |
| 厂商： | Semtech |
| 文件页数： | 12/22页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK ADJ 2A 8SOIC |
| 标准包装： | 1 |
| 类型： | 降压（降压） |
| 输出类型： | 可调式 |
| 输出数： | 1 |
| 输出电压： | 1 V ~ 26.88 V |
| 输入电压： | 3 V ~ 28 V |
| PWM 型： | 电流模式 |
| 频率 - 开关： | 300kHz ~ 1.3MHz |
| 电流 - 输出： | 2A |
| 同步整流器： | 无 |
| 工作温度： | -40°C ~ 105°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 8-SOIC（0.154"，3.90mm Width）裸露焊盘 |
| 包装： | 标准包装 |
| 供应商设备封装： | 8-SOIC-EP |
| 其它名称： | SC4524CSEDKR |
SC4524C
Applications Information (Cont.)
Output Capacitor
The output ripple voltage D V O of a buck converter can be
expressed as
Bootstrapping the Power Transistor
The typical minimum BST-SW voltage required to fully
saturate the power transistor is shown in Figure 5, which
D V O = D I L x ? ? ESR +
? ?
? 1
? 8 x F SW x C O
where C O is the output capacitance.
?
?
is about .96V at room temperature.
Fig.5
Since the inductor ripple current D I L increases as D
decreases (see first Inductor selection equation), the
output ripple voltage is therefore the highest when V IN is
at its maximum.
S S 270 RE V 6-7
Minim
A 0μF to 47μF X5R ceramic capacitor is found adequate
for output filtering in most applications. Ripple current
in the output capacitor is not a concern because the
inductor current of a buck converter directly feeds C O ,
resulting in very low ripple current. Avoid using Z5U
2.2
2.1
2.0
and Y5V ceramic capacitors for output filtering because
these types of capacitors have high temperature and high
voltage coefficients.
Figure 5 — Typical Minimum Bootstrap Voltage
required to Saturate Transistor (I SW = -2.6A)
1.9
1.8
powered from either the input or the output of the -50
FreewheelingDiode
Use of Schottky barrier diodes as freewheeling rectifiers
reduces diode reverse recovery input current spikes,
easing high-side current sensing in the SC4524C. These
diodes should have an average forward current rating
at least 2A and a reverse blocking voltage of at least a
few volts higher than the input voltage. For switching
regulators operating at low duty cycles (i.e. low output
voltage to input voltage conversion ratios), it is beneficial
1.7
The BST-SW voltage is supplied by a bootstrap circuit
1.6
converter (Figure 6(a), 6(b) and 6(c)). To maximize
efficiency, tie the bootstrap diode to the converter output
if V O > 2.5V as shown in Figure 6(a) and 6(c). Since the
bootstrap supply current is proportional to the converter
load current, using a lower voltage to power the bootstrap
circuit reduces driving loss and improves efficiency.
I S W = -2
-25
to use freewheeling diodes with somewhat higher
average current ratings (thus lower forward voltages). This
is because the diode conduction interval is much longer
than that of the transistor. Converter efficiency will be
improved if the voltage drop across the diode is lower.
The 20BQ030 (International Rectifier), B230A (Diodes
Inc.), SS 3, SS23 (Vishay), CMSH -40M, CMSH -40ML and
CMSH2-40M (Central-Semi.) are all suitable.
The freewheeling diode should be placed close to the SW
pin of the SC4524C on the PCB to minimize ringing due to
The bootstrap diode D can be a fast switching PN diode
( N4 48 or N9 4) if V O falls between 3V and 8V as shown
in Figure 6(a). If the converter output voltage is between
2.5V and 3V or higher than 8V, then use a low forward drop
Schottky diode (BAT54 or similar) for D (Figure 6(c)). If V O
is less than 2.5V, then it will be necessary to bootstrap the
SC4524C from V IN (Figure 6(b)). If bootstrapping from V IN
> 20V, then connect a Zener diode D 3 in series with D to
reduce the voltage stress at the BST pin. Figure 6(b) shows
this configuration for V IN > 20V. If bootstrapping from V IN <
20V, then D alone will suffice. D is a PN junction diode as
in Figure 6(a).
trace inductance.
A small ceramic capacitor (0.33uF - 0.47uF) is adequate for
bootstrapping.
2
相关PDF资料 |
PDF描述 |
|---|---|
| SC4524DSETRT | IC REG BUCK ADJ 2A 8SOIC |
| SC4524SETRT | IC REG BUCK 2A 8SOIC |
| SC4525ASETRT | IC REG BUCK 3A 8SOIC |
| SC4525CSETRT | IC REG BUCK ADJ 3A 8SOIC |
| SC4525DSETRT | IC REG BUCK ADJ 3A 8SOIC |
相关代理商/技术参数 |
参数描述 |
|---|---|
| SC4524CSETRT-CUT TAPE | 制造商:SEMTECH 功能描述:SC4524 Series 28 V 2 A 2 MHz Step-Down Switching Regulator - SOIC-8 |
| SC4524D | 制造商:SEMTECH 制造商全称:Semtech Corporation 功能描述:18V 2A Step-Down Switching Regulator 2A Output Current |
| SC4524DSETRT | 功能描述:IC REG BUCK ADJ 2A 8SOIC RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:250 系列:- 类型:降压（降压） 输出类型:固定 输出数:1 输出电压:1.2V 输入电压:2.05 V ~ 6 V PWM 型:电压模式 频率 - 开关:2MHz 电流 - 输出:500mA 同步整流器:是 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:6-UFDFN 包装:带卷 (TR) 供应商设备封装:6-SON（1.45x1） 产品目录页面:1032 (CN2011-ZH PDF) 其它名称:296-25628-2 |
| SC4524EVB | 制造商:SEMTECH 制造商全称:Semtech Corporation 功能描述:Programmable Frequency, 2A Output 30V Step-Down Switching Regulator |
| SC4524SETRT | 功能描述:IC REG BUCK 2A 8SOIC RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,500 系列:- 类型:降压（降压） 输出类型:两者兼有 输出数:1 输出电压:5V，1 V ~ 10 V 输入电压:3.5 V ~ 28 V PWM 型:电流模式 频率 - 开关:220kHz ~ 1MHz 电流 - 输出:600mA 同步整流器:无 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:16-SSOP（0.154"，3.90mm 宽） 包装:带卷 (TR) 供应商设备封装:16-QSOP |
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