参数资料
型号: ISL6420BIRZ-TK
厂商: Intersil
文件页数: 17/21页
文件大小: 0K
描述: IC REG CTRLR BUCK PWM VM 20-QFN
标准包装: 1,000
PWM 型: 电压模式
输出数: 1
频率 - 最大: 1.4MHz
占空比: 100%
电源电压: 4.5 V ~ 28 V
降压:
升压:
回扫:
反相:
倍增器:
除法器:
Cuk:
隔离:
工作温度: -40°C ~ 85°C
封装/外壳: 20-VFQFN 裸露焊盘
包装: 带卷 (TR)
ISL6420B
VIN
Compensation Break Frequency Equations
F Z1 = ----------------------------------
OSC
PWM
COMPARATOR
DRIVER
L O
V OUT
1
2 π ? R 2 ? C1
(EQ. 6)
+
F P1 = -------------------------------------------------------
2 π ? R2 ? ? ---------------------- ?
+
F Z2 = ------------------------------------------------------
F P2 = ----------------------------------
Δ V OSC
-
Z FB
V E/A
-
ERROR
AMP
DRIVER
Z IN
REFERENCE
PHASE
C O
ESR
(PARASITIC)
1
C1 ? C2
? C1 + C2 ?
1
2 π ? ( R1 + R3 ) ? C3
1
2 π ? R3 ? C3
(EQ. 7)
(EQ. 8)
(EQ. 9)
1. Pick Gain (R2/R1) for desired converter bandwidth
DETAILED COMPENSATION COMPONENTS
2. Place 1 ST Zero Below Filter’s Double Pole
C 1
C 2
R 2
Z FB
C 3
Z IN
R 3
V OUT
(~75% F LC )
3. Place 2 ND Zero at Filter’s Double Pole
4. Place 1 ST Pole at the ESR Zero
5. Place 2 ND Pole at Half the Switching Frequency
COMP
-
FB
R 1
6. Check Gain against Error Amplifier’s Open-Loop
Gain
7. Estimate Phase Margin - Repeat if Necessary
+
ISL6420B
REF
R 4
Figure 18 shows an asymptotic plot of the DC/DC
converter’s gain vs. frequency. The actual Modulator Gain
has a high gain peak due to the high Q factor of the
output filter and is not shown in Figure 18. Using the
V OUT = V REF × ? 1 + ------ 1 - ?
F LC = ---------------------------------------
2 π ? L O ? C O
? R ?
? R 4 ?
FIGURE 17. VOLTAGE - MODE BUCK CONVERTER
COMPENSATION DESIGN
Modulator Break Frequency Equations
1
(EQ. 4)
previously mentioned guidelines should give a
Compensation Gain similar to the curve plotted. The
open loop error amplifier gain bounds the compensation
gain. Check the compensation gain at F P2 with the
capabilities of the error amplifier. The Loop Gain is
constructed on the log-log graph of Figure 18 by adding
the Modulator Gain (in dB) to the Compensation Gain (in
dB). This is equivalent to multiplying the modulator
transfer function to the compensation transfer function
and plotting the gain.
F ESR = ---------------------------------------------
1
2 π ? ( ESR ? C O )
(EQ. 5)
100
80
F Z1 F Z2
F P1
F P2
The compensation network consists of the error amplifier
(internal to the ISL6420B) and the impedance networks
Z IN and Z FB . The goal of the compensation network is to
provide a closed loop transfer function with the highest
0dB crossing frequency (f 0dB ) and adequate phase
margin. Phase margin is the difference between the
closed loop phase at f 0dB and 180°. The following
equations relate the compensation network’s poles, zeros
and gain to the components (R 1 , R 2 , R 3 , C 1 , C 2 , and C 3 )
in Figure 17. Use the following guidelines for locating the
poles and zeros of the compensation network.
60
40
20
0
-20
-40
-60
20LOG
(R 2 /R 1 )
MODULATOR
GAIN
10 100 1k
F LC
10k
OPEN LOOP
ERROR AMP GAIN
20LOG
(VIN/ Δ V OSC )
COMPENSATION
GAIN
CLOSED LOOP
GAIN
F ESR
100k 1M 10M
FREQUENCY (Hz)
FIGURE 18. ASYMPTOTIC BODE PLOT OF CONVERTER
GAIN
17
FN6901.1
December 4, 2009
相关PDF资料
PDF描述
B41041C9337M 330UF 100V 16X35.5 SINGLE END
SLPX391M200C1P3 CAP ALUM 390UF 200V 20% SNAP
RCM31DRMI-S288 CONN EDGECARD 62POS .156 EXTEND
B41042A5128M 1200UF 25V 12.5X25 SINGLE END
VE-J4N-EW-F4 CONVERTER MOD DC/DC 18.5V 100W
相关代理商/技术参数
参数描述
ISL6420BMAEP 制造商:Intersil Corporation 功能描述:VOLT MODE PWM CNTRLR 20QSOP W - Rail/Tube
ISL6420BMAEP-TK 制造商:Intersil Corporation 功能描述:VOLT MODE PWM CNTRLR 20QSOP W - Tape and Reel
ISL6420EVAL3 功能描述:EVALUATION BOARD 3 ISL6420 RoHS:否 类别:编程器,开发系统 >> 过时/停产零件编号 系列:- 标准包装:1 系列:- 传感器类型:CMOS 成像,彩色(RGB) 传感范围:WVGA 接口:I²C 灵敏度:60 fps 电源电压:5.7 V ~ 6.3 V 嵌入式:否 已供物品:成像器板 已用 IC / 零件:KAC-00401 相关产品:4H2099-ND - SENSOR IMAGE WVGA COLOR 48-PQFP4H2094-ND - SENSOR IMAGE WVGA MONO 48-PQFP
ISL6420IA 功能描述:IC REG CTRLR BUCK PWM VM 20-QSOP RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:4,000 系列:- PWM 型:电压模式 输出数:1 频率 - 最大:1.5MHz 占空比:66.7% 电源电压:4.75 V ~ 5.25 V 降压:是 升压:无 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:无 工作温度:-40°C ~ 85°C 封装/外壳:40-VFQFN 裸露焊盘 包装:带卷 (TR)
ISL6420IA-TK 功能描述:IC REG CTRLR BUCK PWM VM 20-QSOP RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:4,000 系列:- PWM 型:电压模式 输出数:1 频率 - 最大:1.5MHz 占空比:66.7% 电源电压:4.75 V ~ 5.25 V 降压:是 升压:无 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:无 工作温度:-40°C ~ 85°C 封装/外壳:40-VFQFN 裸露焊盘 包装:带卷 (TR)