- 您现在的位置：买卖IC网 > PDF目录17367 > ISL85033EVAL2Z (Intersil)EVAL BOARD2 FOR ISL85033 PDF资料下载
参数资料
| 型号： | ISL85033EVAL2Z |
| 厂商： | Intersil |
| 文件页数： | 20/26页 |
| 文件大小： | 0K |
| 描述： | EVAL BOARD2 FOR ISL85033 |
| 标准包装： | 1 |
| 系列： | * |
IS L 8 5 0 3 3
where Io [A] is the output load current, R 1 ( ? ) and Rc ( ? ) is the
ESR of the output capacitor Co.
CURRENT SAMPLING TRANSFER FUNCTION H e (S)
In current loop, the current signal is sampled every switching
S
S
H e ( S ) = ------- + -------------- + 1
ω n Q n
ω n
Example: V o = 5V, I o = 3A, f s = 500kHz, f c = 50kHz,
C o = 47μF/R c = 5m ? , then the compensation resistance
R 1 = 96k ? .
The compensation capacitors are:
cycle. Equation 16 shows the transfer function:
2
2
(EQ. 16)
Where Q n and ω n are given by Q n = – -- π - , = ω n = π f s .
^ i
^
L
i L
IL d ^
^ V IN d^
V IN
+
R T
1 + ------------
v o ω esr (EQ. 17)
F 1 ( S ) = ------ = V in --------------------------------------
d ?
------- + -------------- + 1
ω o Q p
ω o
1
1
Where ω esr = ------------- , Q p ≈ R o ----- o - , ω o = --------------
R c C o
LC o
1 + ------
F 2 ( S ) = --- ? - = ------------------- --------------------------------------
R o + R L
(EQ. 18)
d
S
S
ω o Q p
------- + -------------- + 1
ω o
C 1 = 815pF, C 2 = 2.5pF (There is approximately 3pF parasitic
capacitance from V COMP to GND; therefore, C 2 is optional).
Theory of Compensation
The sensed current signal is injected into the voltage loop to
achieve current mode control to simplify the loop compensation
design. The inductor is not considered as a state variable for
current mode control and the system becomes a single order
system. It is much easier to design a compensator to stabilize the
voltage loop than voltage mode control. Figure 46 shows the
small signal model of the synchronous buck regulator.
^
IN V O
1:D
Rc
Ro
Co
2
Power Stage Transfer Functions
Transfer function F 1 (S) from control to output voltage is
calculated in Equation 17:
S
S S
2
C
L
Transfer function F 2 (S) from control to inductor current is given
by Equation 18:
S
I
? o V in ω z
2
2
Where ω z = ------------- .
d ^
Fm
T i (S)
K
1
R o C o
Current loop gain T i (S) is expressed as Equation 19:
+
He(S)
T v (S)
T i ( S ) = R T F m F 2 ( S ) H e ( S )
(EQ. 19)
V COMP
^
-Av(S)
The voltage loop gain with open current loop is calculated in
Equation 20:
FIGURE 46. SMALL SIGNAL MODEL OF SYNCHRONOUS BUCK
REGULATOR
T v ( S ) = KF m F 1 ( S ) A v ( S )
(EQ. 20)
d 1
F m = ---------------- = ------------------------------
( S e + S n ) T s
L v ( S ) = -----------------------
V FB
K = --------- , V
Where
is the feedback voltage of the voltage
V o
PWM Comparator Gain F m
The PWM comparator gain F m for peak current mode control is
given by Equation 14:
(EQ. 14)
v ? comp
Where S e is the slew rate of the slope compensation and S n is
given by Equation 15.
The voltage loop gain with current loop closed is given by
Equation 21:
T v ( S ) (EQ. 21)
1 + T i ( S )
FB
error amplifier. If T i (S)>>1, then Equation 21 can be simplified as
shown in Equation 22:
1 + ------------
L v ( S ) = --------- ------------------- ---------------------- --------------- , ω p ≈ -------------
L
V in – V o
S n = R t --------------------
Where:
(EQ. 15)
S
V FB R o + R L ω esr A v ( S ) 1
S
V o R T 1 + ------- H e ( S ) R o C o
ω p
(EQ. 22)
R T is trans-resistance, and is the product of the current sensing
resistance and gain of the current amplifier in current loop.
20
From Equation 22, it is shown that the system is a single order
system, which has a single pole located at ω P before the half
switching frequency. Therefore, a simple type II compensator can
be easily used to stabilize the system.
FN6676.6
February 23, 2012
相关PDF资料 |
PDF描述 |
|---|---|
| MIC5891BWM | IC DRVR LATCH 8BIT SER IN 16SOIC |
| MIC5891BN | IC DRVR LATCH 8BIT SER IN 16DIP |
| TAAB336K010G | CAP TANT 33UF 10V 10% AXIAL |
| SPX385AS-L-1-2 | IC VREF SHUNT PREC 1.235V 8SOICN |
| A9AAT-1105F | FLEX CABLE - AFE11T/AF11/AFE11T |
相关代理商/技术参数 |
参数描述 |
|---|---|
| ISL85033IRTZ | 功能描述:IC REG BUCK SYNC ADJ 3A 28TQFN 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 |
| ISL85033IRTZ-T | 功能描述:IC REG BUCK SYNC ADJ 3A 28TQFN 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 |
| ISL85033IRTZ-T7A | 功能描述:直流/直流开关调节器 3A STD BUCK REG - 4X 4 TQFN 250 PC REEL RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5 |
| ISL8505IRZ | 制造商:Intersil Corporation 功能描述:PB-FREE DC TO DC POWER SWITCHING, 38LD QFN 5X7 - Rail/Tube |
| ISL8510EVAL1Z | 功能描述:EVALUATION BOARD FOR ISL8510 RoHS:是 类别:编程器，开发系统 >> 评估板 - DC/DC 与 AC/DC（离线）SMPS 系列:- 产品培训模块:Obsolescence Mitigation Program 标准包装:1 系列:True Shutdown™ 主要目的:DC/DC，步升 输出及类型:1，非隔离 功率 - 输出:- 输出电压:- 电流 - 输出:1A 输入电压:2.5 V ~ 5.5 V 稳压器拓扑结构:升压 频率 - 开关:3MHz 板类型:完全填充 已供物品:板 已用 IC / 零件:MAX8969 |
发布紧急采购，3分钟左右您将得到回复。