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环路补偿资料

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  • 日期: 2013-11-08
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标签: 电路

很好的资料,环路补偿很容易

环路补偿很容易 � 确定功率级特性 � 说明 Type II 补偿 – 电流模式 � 阐述 Type III 补偿 – 电压模式 � 补偿电流模式降压 � 找出交越频率和相位裕量 � 使用 Excel 补偿器设计工具 降压 / 正激式 • 降压 / 隔离 升压 • 升压 降压-升压 / 反激式 • 反转极性 / 隔离 降压 / 正激式 升压 降压-升压 / 反激式 L VI N Buck Converter L VI N NP NS Forward Converter VO U T VOUT = VIN ⋅ D VO U T VOUT = VIN ⋅D⋅ NS NP 降压 / 正激式 升压 降压-升压 / 反激式 L VI N VO U T 1 VOUT = VIN ⋅ 1−D Boost Converter 降压 / 正激式 升压 降压-升压 / 反激式 VI N L -VO U T D VOUT = VIN ⋅ 1−D B u c k -Boost Converter VI N NP NS VO U T Flyback Converter VOUT = VIN ⋅ D ⋅ NS 1− D NP 单个极点 单个零点 反相零点 (Inverted Zero) 右半平面零点 共轭复极点 1 H(s) = 1+ s ωP PHASE (°) MAGNITUDE (dB) 20 0 -20 -40 -60 10 100 1,000 10,000 100,000 1,000,000 FREQUENCY (Hz) 45 0 -45 -90 -135 10 100 1,000 10,000 100,000 1,000,000 FREQUENCY (Hz) s 1+ H(s) = ω Z 1 PHASE (°) MAGNITUDE (dB) 60 40 20 0 -20 10 135 90 45 0 -45 10 100 1,000 10,000 100,000 1,000,000 FREQUENCY (Hz) 100 1,000 10,000 100,000 1,000,000 FREQUENCY (Hz) 1+ ωZ H(s) = s 1 PHASE (°) MAGNITUDE (dB) 60 40 20 0 -20 10 100 1,000 10,000 100,000 1,000,000 FREQUENCY (Hz) 45 0 -45 -90 -135 10 100 1,000 10,000 100,000 1,000,000 FREQUENCY (Hz) s 1− H(s) = ω Z 1 PHASE (°) MAGNITUDE (dB) 60 40 20 0 -20 10 100 1,000 10,000 100,000 1,000,000 FREQUENCY (Hz) 45 0 -45 -90 -135 10 100 1,000 10,000 100,000 1,000,000 FREQUENCY (Hz) 1 H(s) = s s2 1+ QO ⋅ ωO + ω 2 O PHASE (°) MAGNITUDE (dB) 20 0 -20 -40 -60 10 Q=2 Q=1 Q=0.5 Q=0.25 100 1,000 10,000 100,000 1,000,000 FREQUENCY (Hz) 90 0 -90 -180 -270 10 100 1,000 10,000 100,000 1,000,000 FREQUENCY (Hz) Q=2 Q=1 Q =0.5 Q =0.25 环路补偿介绍 理想的控制环路 实用的反馈理论 VI N 环路增益是以反馈环路 为中心的增益, 由误差放大器增益和 功率级增益部分组成。 Pow er Stage : Inductor /Transform er Pow er Sw itches M odulator VC C om pensation E rror A m p REF VO U T Test Signal Load GAIN (dB) PHASE (°) 80 60 40 20 0 -20 10 180 135 90 45 0 -45 100 1,000 10,000 100,000 1,000,000 FREQUENCY (Hz) 交越频率 相位裕量 • 控制环路的带宽决定了环路对于某种 瞬态状况的响应速度 • 通常都会优先选择较高的交越频率, 但存在着实际的限制。经验法则是将 其设定为开关频率的 1/5 至 1/10 • 0°(增益裕量) 时的衰减以及开关频率 下的衰减也是很重要的 • 需要充足的相位裕量以避免发生振荡 • 最佳的相位裕量是 52° • 低相位裕量将导致欠阻尼的系统响应 • 较高的相位裕量则导致过阻尼的系统 响应 电压模式降压 电流模式降压 电流模式升压 电流模式降压-升压 VI N Logic PW M + L COU T RE S R VO U T ROU T VRA M P VC A VC = VIN VRAMP QO = R OUT L C OUT ωO = 1 L ⋅ COUT 1 ωZ = R ESR ⋅ C OUT GAIN (dB) 40 A VC 20 ωO 2⋅ π 0 -20 -40 -60 10 ωZ 2⋅ π 100 1,000 10,000 100,000 1,000,000 FREQUENCY (Hz) s 1+ vˆ OUT vˆ C = A VC ⋅ 1+ ωZ s s2 + QO ⋅ ωO ωO2 VI N Logic PW M + L CO U T Ri RE S R + Σ + VS L OP E VC VO U T RO U T A VC ≈ R OUT Ri 1 ωP ≈ C OUT ⋅ R OUT 1 ωZ = R ESR ⋅ C OUT Km ≈ VIN VSLOPE ωL = K m ⋅R i L GAIN (dB) 40 A VC 20 ωP 2⋅π 0 ωL 2⋅π -20 ωZ 2⋅π -40 -60 10 100 1,000 10,000 100,000 1,000,000 FREQUENCY (Hz) s 1+ vˆ OUT vˆ C ≈ A VC ⋅ ωZ ⎜⎜⎛1 + ⎝ s ωP ⎟⎟⎞ ⎠ ⋅ ⎜⎜⎛1 + ⎝ s ωL ⎟⎟⎞ ⎠ VI N CI N L CO U T RS RE S R Σ + + VS L OP E Logic PW M - + VC VO U T RO U T A VC ≈ R OUT ⋅ D′ 2⋅Ri ωP ≈ 2 COUT ⋅ R OUT 1 ωZ = R ESR ⋅ C OUT ωR = R OUT ⋅ D′2 L Km ≈ VOUT VSLOPE ωL = K m ⋅R i L GAIN (dB) 40 A VC 20 0 -20 -40 ωP 2⋅π ωR 2⋅ π ωL 2⋅π ωZ 2⋅ π -60 10 100 1,000 10,000 100,000 1,000,000 FREQUENCY (Hz) vˆ OUT vˆ C ≈ A VC ⋅ ⎛ ⎜⎜⎝1 − s ωR ⎞ ⎟⎟⎠ ⋅ ⎛ ⎜⎜⎝1 + s ωZ ⎞ ⎟⎟⎠ ⎛ ⎜⎜1 + ⎝ s ωP ⎞ ⎟⎟ ⎠ ⋅ ⎛ ⎜⎜1 + ⎝ s ωL ⎞ ⎟⎟ ⎠ VIN L o g ic PW M + L COU T Ri RE S R + Σ+ VS LOP E VC RO U T -VO U T A VC ≈ R OUT ⋅ D′ (1+ D) ⋅ R i ωP ≈ 1+D COUT ⋅ R OUT 1 ωZ = R ESR ⋅ C OUT ωR = R OUT ⋅ D′2 L⋅D Km ≈ VIN + VOUT VSLOPE ωL = K m ⋅R i L GAIN (dB) 40 A VC 20 0 -20 -40 ωP 2⋅π ωR 2⋅ π ωL 2⋅π ωZ 2⋅ π -60 10 100 1,000 10,000 100,000 1,000,000 FREQUENCY (Hz) vˆ OUT vˆ C ≈ A VC ⋅ ⎛ ⎜⎜⎝1 − s ωR ⎞ ⎟⎟⎠ ⋅ ⎛ ⎜⎜⎝1 + s ωZ ⎞ ⎟⎟⎠ ⎛ ⎜⎜1 + ⎝ s ωP ⎞ ⎟⎟ ⎠ ⋅ ⎛ ⎜⎜1 + ⎝ s ωL ⎞ ⎟⎟ ⎠ Type I 误差放大器 Type II 误差放大器 Type II 跨导放大器 Type III 误差放大器 CC OM P VO U T ′ RF B T VF B VC - + VR E F RF B B 1 ωEA = R FBT ⋅ C COMP GAIN (dB) 60 40 20 0 -20 -40 10 ω EA 2⋅ π 100 1,000 10,000 100,000 1,000,000 FREQUENCY (Hz) vˆ C ≈ − ω EA vˆ ′ OUT s VO UT ′ CH F CC OM P RC OM P RF B T VC - VF B + VR E F RF B B A VM ≈ R COMP R FBT 1 ω ZEA = R COMP ⋅ C COMP ωHF ≈ 1 R COMP ⋅ CHF 假设 : CCOMP >> CHF GAIN (dB) 60 40 20 A VM 0 ω ZEA 2⋅ π ωHF 2⋅π -20 10 100 1,000 10,000 100,000 1,000,000 FREQUENCY (Hz) vˆ C vˆ OUT′ ≈ −A VM 1 + ω ZEA ⋅ s 1+ s ωHF VC RC OM P CC OM P CH F RE A VO U T ′ - VF B + VR E F gm RF B T RF B B A VM = K FB ⋅ gm ⋅ R COMP ω ZE A = 1 R COMP ⋅ CCOMP K FB = R FBB R FBB + R FBT 1 ωHF ≈ R COMP ⋅ CHF A OL = gm ⋅ R EA 假设 : CCOMP >> CHF & REA >> RCOMP GAIN (dB) 60 40 20 A VM 0 ω ZEA 2⋅ π ωHF 2⋅π -20 10 100 1,000 10,000 100,000 1,000,000 FREQUENCY (Hz) vˆ C vˆ OUT′ ≈ −A VM 1 + ω ZEA ⋅ s 1+ s ωHF VO U T ′ CH F CF F CC O M P RC O M P RF F VF B VC - + VR E F RF B T RF B B A VM ≈ R COMP R FBT ω ZE A = 1 R COMP ⋅ CCOMP ωFZ ≈ 1 R FBT ⋅ CFF ωFP = 1 R FF ⋅ CFF 1 ωHF ≈ R COMP ⋅ C HF 假设 : CCOMP >> CHF & RFBT >> RFF GAIN (dB) 60 40 ωFP ωHF 2⋅π 2⋅π 20 0 A VM ω ZEA 2⋅ π -20 10 100 1,000 ωFZ 2⋅ π 10,000 FREQUENCY (Hz ) 100,000 1,000,000 vˆ C vˆ OUT′ = −A VM ⋅ ⎛ ⎜⎜⎝1 + ω ZE A s ⎞ ⎟⎟⎠ ⋅ ⎛ ⎜⎜⎝1 + s ωFZ ⎞ ⎟⎟⎠ ⎛ ⎜⎜1 + ⎝ s ωFP ⎞ ⎟⎟ ⎠ ⋅ ⎛ ⎜⎜1 + ⎝ s ωHF ⎞ ⎟⎟ ⎠ 电流模式降压 – Type II 补偿 电流模式升压 – Type II 补偿 电流模式降压-升压 – Type II 补偿 电压模式降压 – Type II 补偿 电压模式降压 – Type III 补偿 调制器 D = VOUT VIN D′ = VIN − VOUT VIN VI N L Logic 输出滤波器 VO U T Ri PW M + + Σ+ O p tim a l V S L OP E = VO U T x R i / L COUT RE S R ROUT Slo p e Com p VS L OP E VC gm + CH F RC OM P C COM P VF B VRE F 误差放大器 RF B T RF B B • 选择一个大的 RFBT 阻值,介于 2 kΩ 和 200 kΩ 之间 • 找出调制器跨导(单位: A/V) • 选择一个目标带宽,通常为 FSW/10 • 设定中频段增益 AVM 以实现目标带宽:ωC = 2·π·FC • 设定 ωZEA = 1/10 目标交越频率: ωZEA = ωC/10 • 设定 ωHF = ESR 零点频率:ωHF = ωZ 1 Gm (mod) = R i R COMP = A VM ⋅ RFBT 1 CCOMP = ω ZEA ⋅ RCOMP 或: A VM = ωC ⋅ CO Gm (mod) R COMP = A VM gm ⋅ K FB 1 CHF = ωHF ⋅ R COMP 功率级 s vˆ OUT vˆ C ≈ A VC 1+ ⋅ ωZ ⎜⎜⎛1 + ⎝ s ωP ⎟⎟⎞ ⎠ ⋅ ⎜⎜⎛1 + ⎝ s ωL ⎟⎟⎞ ⎠ 误差放大器 vˆ C vˆ ′ OUT ≈ −A VM 1 + ω ZEA ⋅ s 1+ s ωHF 控制环路 vˆ OUT = vˆ OUT ⋅ vˆ C vˆ ′ OUT vˆ C vˆ ′ OUT 40 20 A VC 0 -20 -40 10 100 60 40 20 0 -20 10 100 40 20 0 -20 -40 10 100 ωP 2⋅ π 1,000 10,000 ωZ ωL 2⋅π 2⋅ π 100,000 1,000,000 ω ZEA 2⋅ π 1,000 A VM ωHF 2⋅π 10,000 100,000 1,000,000 ωC 2⋅ π 1,000 10,000 100,000 1,000,000 L VI N 输出滤波器 VO U T CI N RS 调制器 +Σ + D = VOUT − VIN VOUT Logic PW M - + D′ = VIN VOUT O p tim a l V S LOP E = ( VO U T – V I N ) x R i / L W here R i = Current Sense Gain x R S CO U T RE S R RO U T S lope C om p VS LOP E VC CH F gm + RC OM P CC O M P VF B VR E F 误差放大 器 RFB T RF B B • 选择一个大的 RFBT 阻值,介于 2 kΩ 和 200 kΩ 之间 • 找出调制器跨导(单位:A/V) • 找出最小输入电压和最大负载电流条件下的 RHPZ 频率 • 将目标带宽设定为 RHPZ 频率的 ¼:ωC = ωR/4 • 设定中频段增益 AVM 以实现目标带宽:ωC = 2·π·FC • 设定 ωZEA = 1/10 的目标交越频率:ωZEA = ωC/10 • 设定 ωHF = RHP 或 ESR 零点频率当中较低的那个:ωHF = ωR 或 ωZ D′ Gm (mod) = R i ωR = R OUT ⋅ D′2 L R COMP = A VM ⋅ RFBT 或: 1 CCOMP = ω ZEA ⋅ RCOMP A VM = ωC ⋅ CO Gm (mod) R COMP = A VM gm ⋅ K FB 1 CHF = ωHF ⋅ R COMP 功率级 vˆ OUT vˆ C ≈ A VC ⋅ ⎛ ⎜⎜1 − ⎝ s ωR ⎞ ⎟⎟ ⎠ ⋅ ⎛ ⎜⎜1 + ⎝ ⎜⎜⎛1+ ⎝ s ωP ⎟⎟⎞ ⎠ ⋅ ⎜⎜⎛1+ ⎝ s ωZ ⎞ ⎟⎟ ⎠ s ωL ⎟⎟⎞ ⎠ 误差放大器 vˆ C vˆ ′ OUT ≈ −A VM 1 + ω ZEA ⋅ s 1+ s ωHF 控制环路 vˆ OUT = vˆ OUT ⋅ vˆ C vˆ ′ OUT vˆ C vˆ ′ OUT 40 20 A VC 0 -20 -40 10 60 40 20 0 -20 10 40 20 0 -20 -40 10 ωP 2⋅ π 100 1,000 ωR ωZ 2⋅ π 2⋅ π ωL 2⋅ π 10,000 100,000 1,000,000 ω ZEA 2⋅ π 100 1,000 ωHF A VM 2 ⋅ π 10,000 100,000 1,000,000 ωC 2⋅π 100 1,000 10,000 100,000 1,000,000 VI N 输出滤波器 调制器 D = VOUT VIN + VOUT Logic L COUT Ri RE S R D′ = VIN VIN + VOUT PW M - + + Σ+ O p tim a l V S L OP E = VO U T x R i / L Slo p e Com p VC gm + CH F R COM P CCOM P ROUT V SLOPE VF B VRE F RF B T RFB B -VOU T 误差放大 器 • 选择一个大的 RFBT 阻值,介于 2 kΩ 和 200 kΩ 之间 • 找出调制器跨导(单位:A/V) • 找出最小输入电压和最大负载电流条件下的 RHPZ 频率 • 将目标带宽设定为 RHPZ 频率的 ¼: ωC = ωR/4 • 设定中频段增益 AVM 以实现目标带宽: ωC = 2·π·FC • 设定 ωZEA = 1/10 的目标交越频率: ωZEA = ωC/10 • 设定 ωHF = RHP 或 ESR 零点频率当中较低的那个: ωHF = ωR 或 ωZ D′ Gm (mod) = R i ωR = R OUT ⋅ D′2 L ⋅D R COMP = A VM ⋅ RFBT 或: 1 CCOMP = ω ZEA ⋅ RCOMP A VM = ωC ⋅ CO Gm (mod) R COMP = A VM gm ⋅ K FB 1 CHF = ωHF ⋅ R COMP 功率级 vˆ OUT vˆ C ≈ A VC ⋅ ⎛ ⎜⎜1 − ⎝ s ωR ⎞ ⎟⎟ ⎠ ⋅ ⎛ ⎜⎜1 + ⎝ ⎜⎜⎛1+ ⎝ s ωP ⎟⎟⎞ ⎠ ⋅ ⎜⎜⎛1+ ⎝ s ωZ ⎞ ⎟⎟ ⎠ s ωL ⎟⎟⎞ ⎠ 误差放大器 vˆ C vˆ ′ OUT ≈ −A VM 1 + ω ZEA ⋅ s 1+ s ωHF 控制环路 vˆ OUT = vˆ OUT ⋅ vˆ C vˆ ′ OUT vˆ C vˆ ′ OUT 40 20 A VC 0 -20 -40 10 60 40 20 0 -20 10 40 20 0 -20 -40 10 ωP 2⋅ π 100 1,000 ωR ωZ 2⋅ π 2⋅ π ωL 2⋅ π 10,000 100,000 1,000,000 ω ZEA 2⋅ π 100 1,000 ωHF A VM 2 ⋅ π 10,000 100,000 1,000,000 ωC 2⋅π 100 1,000 10,000 100,000 1,000,000 调制器 D = VOUT VIN D′ = VIN − VOUT VIN VI N L Logic VR A M P PW M T - + VC 输出滤波器 CO U T RE S R RO U T CH F CF F CC O M P RC O M P RF F - VF B + VR E F VO UT 误差放大 器 RF B T RF B B • 与高 ESR 输出电容器配合使用 • 选择一个大的 RFBT 阻值,介于 2 kΩ 和 200 kΩ 之间 • 设定中频段增益 AVM 以获得期望的带宽 • 设定 ωZEA = 输出滤波器共轭复极点 ωO • 设定 ωHF = ½ 开关频率: ωHF = 2·π·FSW/2 R COMP = A VM ⋅ RFBT 1 CCOMP = ω ZEA ⋅ R COMP 1 CHF = ωHF ⋅ R COMP • 与低 ESR输出电容器配合使用 • 选择一个大的 RFBT 阻值,介于 2 kΩ 和 200 kΩ 之间 • 设定中频段增益 AVM 以实现目标带宽:ωC = 2·π·FC • 设定 ωZEA 和 ωFZ = 输出滤波器共轭复极点 ωO • 设定 ωFP = 输出滤波器零点 ωZ • 设定 ωHF = ½ 开关频率: ωHF = 2·π·FSW/2 A VM = ωC A VC ⋅ ωO 1 CFF = ωFZ ⋅ R FBT R COMP = A VM ⋅ RFBT 1 RFF = ωFP ⋅ CFF 1 CCOMP = ω ZEA ⋅ RCOMP 1 CHF = ωHF ⋅ R COMP 功率级 s vˆ OUT vˆ C ≈ A VC ⋅ 1+ 1+ ωZ s s2 + Q O ⋅ ωO ωO2 误差放大器 vˆ C vˆ OUT′ ≈ −A VM ⋅ ⎛ ⎜⎜1 + ⎝ ω ZEA s ⎞ ⎟⎟ ⋅ ⎠ ⎜⎜⎝⎛1 + s ωFZ ⎟⎟⎠⎞ ⎜⎜⎛1 + ⎝ s ω FP ⎟⎟⎞ ⎠ ⋅ ⎜⎜⎛1 + ⎝ s ωHF ⎟⎟⎞ ⎠ 控制环路 vˆ OUT = vˆ OUT ⋅ vˆ C vˆ ′ OUT vˆ C vˆ ′ OUT 40 20 0 A VC -20 -40 -60 10 60 40 20 0 -20 10 40 20 0 -20 -40 10 ωO 2⋅π 100 1,000 10,000 ω ZEA & ω FZ 2⋅ π 2⋅ π A VM 100 1,000 10,000 ωC 2⋅ π 100 1,000 10,000 ωZ 2⋅π 100,000 1,000,000 ωFP ωHF 2⋅π 2⋅ π 100,000 1,000,000 100,000 1,000,000 需要关注的是: • 误差放大器必须驱动的阻抗 • 误差放大器的带宽 • 误差放大器的开环增益 • LC 滤波器的 Q 值 测量选项 1: 瞬态响应测试 • 简单易行 • 无需专用设备 2: 伯德图 • 需要网络分析仪以获得完整的曲线图 • 可利用普通的测试设备获得关键性的数据 点 瞬态测试 负载阶跃实例 伯德图与瞬态 用于瞬态测试的简单电路 VOUT 针对一个从 0V 至大约比 VOUT 高 5V 的脉冲幅度 及 100Hz 左右的频率来 设置发生器。负载将跟随 发生器的上升 /下降时间。 脉冲发生器 RLoad 增设用于设定最小负载的 DC 负载箱。VOUT/RLOAD 设定了 ΔI。 GND 典型的瞬态响应测试 负载电流 每格 1A 输出电压 每格 50 mV 时标 每格 100 μs fC = 10 kHz, PM = 65 ° 过阻尼 Vg = 3.6V 欠冲 134 mV 过冲 144 mV VOUT IOUT 每格 100 mV AC 耦合 400 mA 200 mA 每格 100 μs fC = 36 kHz, PM = 48 ° 临界阻尼 Vg = 3.6V 欠冲 68 mV 过冲 70 mV VOUT I OUT 每格 100 mV AC 耦合 400 mA 200 mA 每格 100 μs fC = 61 kHz, PM = 17 ° 欠阻尼 Vg = 3.6V 欠冲 68 mV 过冲 64 mV VOUT IOUT 振铃指示 低相位裕量 每格 100 mV AC 耦合 400 mA 200 mA 每格 100 μs fC = 27 kHz, PM = 8 ° 不稳定的稳压器 每格 100 mV AC 耦合 VOU T I OU 400 mA T 200 mA 每格 100 μs 网络分析仪测量 正弦波注入 穿越频率和相位裕量 Loop G ain 环路增益 = 20 ⋅ lo g10 ⎛ ⎜⎜⎝ ν(B) ν(A) ⎞ ⎟⎟⎠ Measurem ent Point B AC siganl in jectio n Network A nalyzer Measurem ent Point A 相位 = phase ⎜⎜⎝⎛ ν(B) ν(A) ⎟⎟⎠⎞ VI N Pow er Stage Pow er Sw itches M odulator VO U T OUT VC C om pensation 10 to 100 Ohm s IN Load RL O A D CL O AD E rror A m p REF Low Voltage S ide A udio G e n e ra to r Audio Transformer Connectoscilloscope channel 1 to O U T , channel 2 to IN . Both relative to the local controller ground . 输出 输入 LM5576 – 500 kHz 开关频率 24V VIN 5V VOUT 1A 负载 幅度 120 mV pk-pk 26.5 kHz 交越频率 相位裕量 = 40.5° 注意光标 时间差 = 4.225 μs 在 26.5 kHz,周期为 37.7 μs。 (4.225/37.7)*360 = 40.5 采用负载阶跃补偿降压稳压器 运用信号注入得到穿越频率和相位裕量 VI N Logic L CO U T PU LSE Ri RE S R RLOAD G EN . VO U T PW M + + Σ+ O p tim a l V S L OP E = VO U T x R i / L Slo p e Com p VS L OP E VC gm + CH F RC OM P C COM P VF B VRE F RF B T RF B B VI N Pow er Stage Pow er Sw itches M odulator VO U T OUT VC C om pensation 10 to 100 Ohm s IN Load RL O A D CL O AD E rror A m p REF Low Voltage S ide Audio Transformer A udio G e n e ra to r Connectoscilloscope channel 1 to O U T , channel 2 to IN . Both relative to the local controller ground . 峰值电流模式降压 – Type II 跨导放大器 峰值电流模式控制 – Type II 电压放大器 电压模式降压 – Type III 电压放大器 电流模式简化频率补偿 Compensator Design - Peak Current-Mode Buck - Transconductance Amplifier Enter parameters in shaded cells V ersion 2.0 Vin (V) 10 PCM1 Frequency Compensation Parameters Error Amplifier - Single Pole Transconductance Amplifier Revision date: 9 May 2010 Vout (V) 5 Reference Voltage Vref (V) 1.2 5 M odulator Error Amp Load Current Iout (A) 1 Bottom Feedback Divider Rfbb (Ω) 1,250 D = 0.5000 Kfb = 0.2500 Switching Frequency Fsw (kHz) 250 Top Feedback Divider Rfbt (Ω) 3,750 Rout = 5.0 0 Avm = 8.250 Current Sense Resistor Rs (mΩ) 10.0 Modulator Scale Factor SFM (V/V) 1.0 0 Ri = 0.1000 khf = 1.010 Current Sense Gain A (V/V) 10 Modulator Gain Gm(mod) (A/V) 10.00 Vsl = 0.4000 wzea = 25,253 Slope Comp Multiplier SLM (V/V) 1 Modulator Crossover Fc(mod) (kHz) 3.1 8 Km = 25.00 whf = 2,550,505 Output Inductor L (μH) 5 .0 Error Amp Zero (kHz) 4.0 2 Kd = 3.000 wbw = 62,831,853 Output Capacitor Cout (μF) 500 Target Loop Bandwidth Fc (kHz) 25.00 Av = 16.667 Slope Comp Output Capacitor ESR (mΩ) 1 .0 Error Amplifier Aol (V/V) 1,000 wp = 1,200 Se = 100000 Error Amplifier gm (μA/V) 1,000 Error Amplifier UGB (MHz) 10 .0 wz = 2,000,000 Sn = 100000 Error Amplifier Rea (kΩ) 1,000 Error Amplifier Cbw (pF) 16 wc = 157,080 wn = 785,398 Q = 0.6366 Gain (dB) Phase (deg) Gain (dB) Phase (deg) 40 20 0 -20 -40 -60 1 Modulator Gain/Phase V comp to V out 0 -30 -60 -90 -120 -150 10 100 1,000 10,000 100,000 1,000,000 Frequency (Hz) 100 80 60 40 20 0 -20 -40 -60 1 Control Loop Gain/Phase 150 120 90 60 30 0 -30 -60 -90 10 100 1,000 10,000 100,000 1,000,000 Frequency (Hz) Compensator Design - Peak Current-Mode Buck - Voltage Amplifier Enter parameters in shaded cells V ersion 2.0 Vin (V) 12 PCM1 Frequency Compensation Parameters Error Amplifier - Single Pole Operational Amplifier Revision date: 9 May 2010 Vout (V) 5 M odulator Error Amp Load Current Iout (A) 1 Reference Voltage Vref (V) 1.2 5 D = 0.4167 Kfb = 0.2500 Switching Frequency Fsw (kHz) 250 Bottom Feedback Divider Rfbb (Ω) 1,250 Rout = 5.0 0 Rth = 937.5 Current Sense Resistor Rs (mΩ) 10.0 Top Feedback Divider Rfbt (Ω) 3,750 Ri = 0.1000 Avm = 8.000 Current Sense Gain A (V/V) 10 Vsl = 0.4000 khf = 1.008 Slope Comp Multiplier SLM (V/V) 1 Modulator Scale Factor SFM (V/V) 1.0 0 Km = 25.00 wzea = 27,778 Output Inductor L (μH) 5 .0 Modulator Gain Gm(mod) (A/V) 10.00 Kd = 3.000 whf = 3,361,111 Output Capacitor Cout (μF) 500 Modulator Crossover Fc(mod) (kHz) 3.1 8 Av = 16.667 wbw = 62,831,853 Output Capacitor ESR (mΩ) 1 .0 wp = 1,200 Slope Comp Error Amp Aol (V/V) 10,000 Error Amp Zero (kHz) 4.4 2 wz = 2,000,000 Se = 100000 Error Amp UGB (MHz) 10 .0 Target Loop Bandwidth Fc (kHz) 25.00 wc = 157,080 Sn = 140000 wn = 785,398 Q = 0.6366 Gain (dB) Phase (deg) Gain (dB) Phase (deg) 40 20 0 -20 -40 -60 1 Modulator Gain/Phase V comp to V out 0 -30 -60 -90 -120 -150 10 100 1,000 10,000 100,000 1,000,000 Frequency (Hz) 100 80 60 40 20 0 -20 -40 -60 1 Control Loop Gain/Phase 150 120 90 60 30 0 -30 -60 -90 10 100 1,000 10,000 100,000 1,000,000 Frequency (Hz) Compensator Design - Voltage-Mode Buck - Voltage Amplifier Enter parameters in shaded cells V ersion 2.1 Frequency Compensation Parameters Error Amplifier - Single Pole Operational Amplifier Revision date: 10 May 2010 Vin (V) 12 Input Voltage Feed-Forward Kff (V/V) 0.1 00 M odulator Vout (V) 1 .8 Equivalent Ramp Voltage Vramp (V) 1.200 D = 0.1500 Kfb = Load Current Iout (A) 10 Reference Voltage Vref (V) 0.600 Rout = 0.1 8 Rth = Switching Frequency Fsw (kHz) 500 Bottom Feedback Divider Rfbb (Ω) 1,500 Km = 10.00 Avm = Top Feedback Divider Rfbt (Ω) 3,000 Gc = 1.054 khf = Output Inductor L (μH) 1 .0 wp = 44,721 wfz = Output Capacitor Cout (μF) 500 Error Amp Aol (V/V) 3,300 wc = 471,239 wzea = Output Capacitor ESR (mΩ) 1 .0 Error Amp UGB (MHz) 15 .0 wz = 2,000,000 wfp = wsw = 3,141,593 whf = Modulator Scale Factor SFM (V/V) 1. 00 Target Loop Bandwidth Fc (kHz) 75.00 wbw = Error Amp 0.333 3 1000 .0 1.06 9 1.01 4 44,72 1 44,72 1 2,00 0,000 3,14 1,593 94,24 7,78 0 Gain (dB) Phase (deg) Gain (dB) Phase (deg) 40 20 0 -20 -40 -60 -80 1 Modulator Gain/Phase V comp to V out 0 -30 -60 -90 -120 -150 -180 10 100 1,000 10,000 100,000 1,000,000 Frequency (Hz) 100 80 60 40 20 0 -20 -40 1 Control Loop Gain/Phase 150 120 90 60 30 0 -30 -60 10 100 1,000 10,000 100,000 1,000,000 Frequency (Hz) Gain / dB Phase / degrees Word 文档 Current-Mode Simplified Frequency Compensation Peak Current-Mode Buck – Voltage Amplifier S1 10 Ri = Gi*Rs K m = Vin*Fm Vin 10 V ramp Fm Vc Gi V slop e V sl = V o*Ri*T/L U1 d SQ R QN Vclo ck T = 5us 5u L S2 47 p 4 .7n Chf 16 k C co mp R comp Gv 1.6 Vlim A ol = 10000 UGB = 10 MHz V fb 1.21 5 Vref 10 m Rs AC 1 0 V1 V o' 3 .74 k Rfbt 1 .21 k R fbb Vo = 5V 330u Co 1 Ro 1m Rc Figure 1. Current-mode buck s witching model. Y2 Y1 Peak CM Buck Control-to-Output 20 50 10 0 0 -50 -10 - 100 -20 - 150 -30 - 200 -40 100 200 500 1k 2k 5k 10k 20k 50k 100k 200k freq / Hertz Pha s e Gai n Figure 2. Control-to-output gain and phase. 嵌入式 Excel • 降压(采用理想运算放大器) • 降压(采用理想跨导放大器) • 升压(采用理想运算放大器) • 升压(采用理想跨导放大器) • 降压-升压(采用理想运算放大器) • 降压-升压(采用理想跨导放大器) 结论 1 • 采用 Excel 补偿器设计工具 2 • 运用瞬态负载验证性能 3 • 采用信号注入进行单位增益和相位测量
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