参数资料
型号: LX1676-CLQTR
厂商: MICROSEMI CORP-ANALOG MIXED SIGNAL GROUP
元件分类: 稳压器
英文描述: 1.5 A SWITCHING CONTROLLER, 1100 kHz SWITCHING FREQ-MAX, PQCC38
封装: PLASTIC, MLPQ-38
文件页数: 4/16页
文件大小: 387K
代理商: LX1676-CLQTR
LX1676
PRELIMINARY DATA SHEET
Microsemi
Integrated Products Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 12
WWW
.Microse
m
i
.CO
M
Mobile AMD Athlon
VRM Controller
I N T E GR A T ED
PRODUCT S
Copyright
2000
Revision: 0.4b, 9/14/2004
TH EORY OF O PERATION (CONTINUED)
LOOP GAIN AUTOMATIC COMPENSATION
The PWM ramp shown in Figure 5 is automatically
adjusted to keep its amplitude fixed ratio to Vin over the
range of 6 to 24 V input.
This maintains a constant loop gain that is set by the
feedback networks around the error amplifiers independent
of PWM input voltage.
TRANSIENT CORRECTION LOOP
Phase 3 is a Transient Correction Loop that can sum a
large amount of current into the output node when required
by an out of range condition. The differential feedback
summing amplifier is connected directly to the output
terminals and has sufficient bandwidth to follow any fast
changes in output voltage. The feedback error voltage is
compared to the commanded reference voltage (DACOUT)
by two high speed comparators, I-Max and I-Min. The
other inputs of these
comparators are offset from the
DACOUT as shown in Fig 6. If the error in output voltage
exceeds the offset in either direction the appropriate
MOSFET will be turned on to force current into or out of
the output node to correct the voltage error. The very low
value inductor (100nH) allows large amounts of current to
be forced into or out of the output node very quickly.
When the Transient Correction Loop is switching it
forces the appropriate upper or lower MOSFETs in phases
1 and 2 to stay on (100% or 0% duty cycle) until the error
is corrected.
The two drivers for the Transient Correction Loop have
outputs (I-Max) and (I-Min) that may be used to drive a
half bridge to correct for both low and high output voltage
conditions. This permits pulling the output low if an
overshoot occurs due to a rapid reduction in load current.
With a conventional Buck regulator rapid changes in the
negative direction are not possible due to the low voltage
available as a forcing function.
The two outputs (I-MAX and I-MIN) are completely
independent. A single MOSFET and diode can be used to
correct for voltage droop only or voltage overshoot only
when driven by the appropriate output. If the I-MAX driver
is not used the VC3 and VS3 pins must be connected to +5
volts.
Under normal operation the Transient Correction phase
is only active for a very brief time during high di/dt loads
on the output.
VC3
I-Min
PGN3
-
35mV
VS3
I-Max
VCCL
I-Min
Comparator
I-Max
Comparator
FB -
FB +
+
-
DACOUT
Differential Feedback
From Output
+
-
70nH
Vout
+5
Figure 6 – Phase 3 Transient Correction Loop
AA
PP
LL
IICC
AA
TT
IIOO
NN
SS
相关PDF资料
PDF描述
LX1676-CPWTR 1.5 A SWITCHING CONTROLLER, 1100 kHz SWITCHING FREQ-MAX, PDSO38
LX1732CDUT 1 A SWITCHING REGULATOR, 135 kHz SWITCHING FREQ-MAX, PDSO8
LX1801CLQ SPECIALTY ANALOG CIRCUIT, PQCC16
LX1801CLQ-TR SPECIALTY ANALOG CIRCUIT, PQCC16
LY5150ALH SPECIALTY ANALOG CIRCUIT, PBGA16
相关代理商/技术参数
参数描述
LX1676CPW 功能描述:IC CTRLR PS VRM BIPHASE 38TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 标准包装:2,000 系列:- 应用:控制器,DSP 输入电压:4.5 V ~ 25 V 输出数:2 输出电压:最低可调至 1.2V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:30-TFSOP(0.173",4.40mm 宽) 供应商设备封装:30-TSSOP 包装:带卷 (TR)
LX1676-CPW 制造商:MICROSEMI 制造商全称:Microsemi Corporation 功能描述:Mobile AMD AthlonTM VRM Controller
LX1677 制造商:MICROSEMI 制造商全称:Microsemi Corporation 功能描述:AMD64 Processor VRM Controller
LX1677 EVAL KIT 制造商:Microsemi Corporation 功能描述:PWM CONTROLLERS - Bulk
LX1677CLQ 功能描述:IC CTRLR VRM PS 2PHASE 38MLPQ RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,000 系列:- 应用:电源,ICERA E400,E450 输入电压:4.1 V ~ 5.5 V 输出数:10 输出电压:可编程 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:42-WFBGA,WLCSP 供应商设备封装:42-WLP 包装:带卷 (TR)