参数资料
| 型号： | ISL62873HRUZ-T |
| 厂商： | Intersil |
| 文件页数： | 13/17页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM 16UTQFN |
| 标准包装： | 3,000 |
| 系列： | Robust Ripple Regulator™ (R³) |
| PWM 型： | 控制器 |
| 输出数： | 1 |
| 频率 - 最大： | 330kHz |
| 电源电压： | 3.3 V ~ 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： | -10°C ~ 100°C |
| 封装/外壳： | 16-UFQFN |
| 包装： | 带卷 (TR) |
ISL62873
has been designed with low pull-down resistance and high
sink current capability to ensure clamping the MOSFETs
gate voltage below V GS(th) .
C INT = 100pF
R COMP
C COMP
-
FB
R FB
V OUT
1V
UGATE
1V
COMP
EA
+
SREF
R OFS
FIGURE 9. COMPENSATION REFERENCE CIRCUIT
1V
1V
The LC output filter has a double pole at its resonant frequency
that causes rapid phase change. The R 3 modulator used in the
IC makes the LC output filter resemble a first order system in
V O
s ? R FB ? C INT ? ( 1 + s ? R COMP ? C
V O ? ( 1 – D )
I P-P = -------------------------------
LGATE
FIGURE 8. GATE DRIVER ADAPTIVE SHOOT-THROUGH
Adaptive Shoot-Through Protection
Adaptive shoot-through protection prevents a gate-driver
output from turning on until the opposite gate-driver output
has fallen below approximately 1V. The dead-time shown in
Figure 8 is extended by the additional period that the falling
gate voltage remains above the 1V threshold. The high-side
gate-driver output voltage is measured across the UGATE
and PHASE pins while the low-side gate-driver output
voltage is measured across the LGATE and PGND pins. The
power for the LGATE gate-driver is sourced directly from the
PVCC pin. The power for the UGATE gate-driver is supplied
by a boot-strap capacitor connected across the BOOT and
PHASE pins. The capacitor is charged each time the phase
node voltage falls a diode drop below PVCC such as when
the low-side MOSFET is turned on.
Compensation Design
Figure 9 shows the recommended Type-II compensation
circuit. The FB pin is the inverting input of the error amplifier.
The COMP signal, the output of the error amplifier, is inside the
chip and unavailable to users. C INT is a 100pF capacitor
integrated inside the IC, connecting across the FB pin and the
COMP signal. R FB , R COMP , C COMP and C INT form the Type-II
compensator. The frequency domain transfer function is given
by Equation 21:
1 + s ? ( R FB + R COMP ) ? C COMP
)
G COMP ( s ) = --------------------------------------------------------------------------------------------------------------- (EQ. 21)
COMP
which the closed loop stability can be achieved with the
recommended Type-II compensation network. Intersil provides
a PC-based tool that can be used to calculate compensation
network component values and help simulate the loop
frequency response.
General Application Design Guide
This design guide is intended to provide a high-level
explanation of the steps necessary to design a single-phase
power converter. It is assumed that the reader is familiar with
many of the basic skills and techniques referenced in the
following. In addition to this guide, Intersil provides complete
reference designs that include schematics, bills of materials,
and example board layouts.
Selecting the LC Output Filter
The duty cycle of an ideal buck converter is a function of the
input and the output voltage. This relationship is expressed
in Equation 22:
D = --------- (EQ. 22)
V IN
The output inductor peak-to-peak ripple current is expressed
in Equation 23:
(EQ. 23)
F SW ? L
A typical step-down DC/DC converter will have an I P-P of
20% to 40% of the maximum DC output load current. The
value of I P-P is selected based upon several criteria such as
MOSFET switching loss, inductor core loss, and the resistive
loss of the inductor winding. The DC copper loss of the
inductor can be estimated using Equation 24:
P COPPER = I LOAD ? DCR
2
(EQ. 24)
Where, I LOAD is the converter output DC current.
The copper loss can be significant so attention has to be given
to the DCR selection. Another factor to consider when choosing
the inductor is its saturation characteristics at elevated
13
FN6930.1
August 31, 2010
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| ISL62875 | 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:PWM DC/DC Controller with VID Inputs for Portable GPU Core-Voltage Regulator |
| ISL62875HRUZ-T | 功能描述:IC REG CTRLR BUCK PWM 20UTQFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:Robust Ripple Regulator™ (R³) 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:275kHz 占空比:50% 电源电压:18 V ~ 110 V 降压:无 升压:无 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:是 工作温度:-40°C ~ 85°C 封装/外壳:8-SOIC（0.154"，3.90mm 宽） 包装:带卷 (TR) |
| ISL62881 | 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:Single-Phase PWM Regulator for IMVP-6.5? Mobile CPUs and GPUs |
| ISL62881_10 | 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:Single-Phase PWM Regulator for IMVP-6.5a?￠ Mobile CPUs and GPUs |
| ISL62881B | 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:Single-Phase PWM Regulator for IMVP-6.5? Mobile CPUs and GPUs |
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