- 您现在的位置：买卖IC网 > PDF目录33797 > 45IZ (Intersil Corporation) 5V or 12V Single Synchronous Buck Pulse-Width Modulation (PWM) Controller PDF资料下载
参数资料
| 型号： | 45IZ |
| 厂商： | Intersil Corporation |
| 英文描述： | 5V or 12V Single Synchronous Buck Pulse-Width Modulation (PWM) Controller |
| 中文描述： | 单5V或12V同步降压脉宽调制（PWM）控制器 |
| 文件页数： | 6/16页 |
| 文件大小： | 302K |
| 代理商： | 45IZ |
www.DataSheet4U.com
14
FN6305.3
November 15, 2006
BOOTSTRAP Considerations
Figure 11 shows the upper gate drive (BOOT pin) supplied by
a bootstrap circuit from VCC. The boot capacitor, CBOOT,
develops a floating supply voltage referenced to the PHASE
pin. The supply is refreshed to a voltage of VCC less the boot
diode drop (VD) each time the lower MOSFET, Q2, turns on.
Check that the voltage rating of the capacitor is above the
maximum VCC voltage in the system; a 16V rating should be
sufficient for a 12V system. A value of 0.1F is typical for
many systems driving single MOSFETs.
If VCC is 12V, but VIN is lower (such as 5V), then another
option is to connect the BOOT pin to 12V, and remove the
BOOT cap (although, you may want to add a local cap from
BOOT to GND). This will make the UGATE VGS voltage
equal to (12V - 5V = 7V). That should be high enough to
drive most MOSFETs, and low enough to improve the
efficiency slightly. Do NOT leave the BOOT pin open, and try
to get the same effect by driving BOOT through VCC and the
internal diode; this path is not designed for the high current
pulses that will result.
For low VCC voltage applications where efficiency is very
important, an external BOOT diode (in parallel with the
internal one) may be considered. The external diode drop
has to be lower than the internal one; the resulting higher
VG-S of the upper FET will lower its rDS(ON). The modest
gain in efficiency should be balanced against the extra cost
and area of the external diode.
For information on the Application circuit, including a
complete Bill-of-Materials and circuit board description, can
be found in Application Note AN1257.
+VCC
ISL6545
GND
LGATE/OCSET
UGATE
PHASE
BOOT
VCC
+VIN
VG-S ≈ VCC - VD
VG-S ≈ VCC
CBOOT
Q1
Q2
+
-
FIGURE 11. UPPER GATE DRIVE BOOTSTRAP
VCC
+ VD -
ISL6545, ISL6545A
相关PDF资料 |
PDF描述 |
|---|---|
| 45L(R)SERIES | Dual/Triple Ultra-Low-Voltage SOT23 µP Supervisory Circuits |
| 45L(R) | STANDARD RECOVERY DIODES Stud Version |
| 45L100 | Standard Recovery Diodes(标准修复二极管) |
| 45L10 | STANDARD RECOVERY DIODES Stud Version |
| 45L120D | Standard Recovery Diodes(标准修复二极管) |
相关代理商/技术参数 |
参数描述 |
|---|---|
| 45J100 | 功能描述:线绕电阻器 - 透孔 5watt 100ohm 5% Axial RoHS:否 制造商:Bourns 电阻:10 Ohms 容差:5 % 功率额定值:7 W 温度系数:200 PPM / C 系列:FW 端接类型:Axial 工作温度范围:- 55 C to + 155 C 尺寸:9.5 mm Dia. x 26 mm L 封装:Ammo 产品:Power Resistors Wirewound High Energy |
| 45J100E | 功能描述:线绕电阻器 - 透孔 5watt 100ohm 5% Axial RoHS:否 制造商:Bourns 电阻:10 Ohms 容差:5 % 功率额定值:7 W 温度系数:200 PPM / C 系列:FW 端接类型:Axial 工作温度范围:- 55 C to + 155 C 尺寸:9.5 mm Dia. x 26 mm L 封装:Ammo 产品:Power Resistors Wirewound High Energy |
| 45J10K | 功能描述:线绕电阻器 - 透孔 5watt 10K 5% Axial RoHS:否 制造商:Bourns 电阻:10 Ohms 容差:5 % 功率额定值:7 W 温度系数:200 PPM / C 系列:FW 端接类型:Axial 工作温度范围:- 55 C to + 155 C 尺寸:9.5 mm Dia. x 26 mm L 封装:Ammo 产品:Power Resistors Wirewound High Energy |
| 45J10KE | 功能描述:线绕电阻器 - 透孔 5watt 10K 5% Axial RoHS:否 制造商:Bourns 电阻:10 Ohms 容差:5 % 功率额定值:7 W 温度系数:200 PPM / C 系列:FW 端接类型:Axial 工作温度范围:- 55 C to + 155 C 尺寸:9.5 mm Dia. x 26 mm L 封装:Ammo 产品:Power Resistors Wirewound High Energy |
| 45J10R | 功能描述:线绕电阻器 - 透孔 5watt 10ohm 5% Axial RoHS:否 制造商:Bourns 电阻:10 Ohms 容差:5 % 功率额定值:7 W 温度系数:200 PPM / C 系列:FW 端接类型:Axial 工作温度范围:- 55 C to + 155 C 尺寸:9.5 mm Dia. x 26 mm L 封装:Ammo 产品:Power Resistors Wirewound High Energy |
发布紧急采购，3分钟左右您将得到回复。