參數資料
型號: IRU3073CQTR
廠商: International Rectifier
文件頁數: 6/21頁
文件大?。?/td> 236K
描述: IC REG DL BCK/LINEAR 16-QSOP
標準包裝: 1
拓撲: 降壓(降壓)同步(1),線性(LDO)(1)
功能: 任何功能
輸出數: 2
頻率 - 開關: 210kHz ~ 400kHz
電壓/電流 - 輸出 1: 控制器
電壓/電流 - 輸出 2: 0.8 V ~ 22.5 V,65mA
帶 LED 驅動器:
帶監(jiān)控器:
帶序列發(fā)生器:
電源電壓: 4.4 V ~ 25 V
工作溫度: 0°C ~ 70°C
安裝類型: 表面貼裝
封裝/外殼: 16-SSOP(0.154",3.90mm 寬)
供應商設備封裝: *
包裝: 剪切帶 (CT)
其它名稱: *IRU3073CQTR
IRU3073CQCT
6
Rev. 1.0
09/17/03
IRU3073
www.irf.com
LDO Controller
The LDO section is powered directly from Vcc. The out-
put of LDO can be set as low as 0.8V and can be pro-
grammed to higher voltages by using two external resis-
tors.
Supply Voltage Under-Voltage Lockout
The under-voltage lockout circuit assures that the
MOSFET driver outputs, remain in the off state when-
ever the supply voltage drops below set parameters. Lock-
out occurs if Vcc or VcH fall below 4.0V and 3.3V re-
spectively. Normal operation resumes once these volt-
ages rise above the set values.
Shutdown
The PWM section can be shutdown by pulling the soft-
start pin below 0.4V. The control MOSFET turns off and
the synchronous MOSFET turns on during shutdown.
Over-Current Protection
Over-current protection is achieved with a cycle by cycle
scheme and it is performed by sensing current through
the RDS(ON) of low side MOSFET. As shown in Figure 5,
an external resistor (RSET) is connected between OCSet
pin and the drain of low side MOSFET (Q2) and sets the
current limit set point. The internal current source devel-
ops a voltage across RSET. When the low side switch is
turned on, the inductor current flows through the Q2 and
results a voltage which is given by:
Figure 5 - Diagram of the over current sensing.
When voltage VOCSET is below zero, the current sensing
comparator flips and disables the oscillator. The high
side MOSFET is turned off and the low side MOSFET is
turned on until the inductor current reduces to below
current set value. The critical inductor current can be
calculated by setting:
CSS = 20mA3TSTART/1V
20mA3TSTART/CSS = 2V-1V
Soft-Start
Voltage
Voltage at negative input
of Error Amp and Feedback
UVLO comparator
Voltage at Fb1 pin
Current flowing
into Fb1 pin
64uA
0uA
0V
0.8V
E1.6V
0.8V
0V
3V
E2V
E1V
Output of UVLO
POR
The feedback voltage increases linearly as the injecting
current goes down. The injecting current drops to zero
when soft-start voltage is around 2V and the output volt-
age goes into steady state.
As shown in Figure 4, the positive pin of feedback UVLO
comparator is always higher than 0.4V, therefore, feed-
back UVLO is not functional during soft-start.
Figure 4 - Theoretical operation waveforms
during Soft-Start.
From this analysis, the output start-up time is defined
as when soft-start capacitor voltage increases from 1V
to 2V. The start-up time will be dependent on the size of
the external soft-start capacitor and can be estimated
by:
For a given start up time, the soft-start capacitor can be
calculated as:
MOSFET Drivers
The driver capabilities of both high and low side drivers
are optimized to maintain fast switching transitions. They
are sized to drive a MOSFET that can deliver up to 20A
output current.
The low side MOSFET diver is supplied directly by VCC
while the high side driver is supplied by VC.
An internal dead time control is implemented to prevent
cross-conduction and allows the use of several kinds of
MOSFETs.
VOCSET = IOCSET3RSET-RDS(ON)3iL  ---(1)
L1
RSET
IRU3073
OCSet
IOCSET
VOUT
Osc
Q1
Q2
ISET = IL(CRITICAL) = ---(2)
RSET3IOCSET
RDS(ON)
VOCSET = IOCSET3RSET - RDS(ON)3IL = 0
相關PDF資料
PDF描述
ISL25700FRUZ-TK IC TEMP SWITCH MFET DRVR 10TQFN
ISL6150IB IC CTRLR HOT PLUG NEG VOLT 8SOIC
ISL6151IB-T IC CTRLR HOT PLUG NEG VOLT 8SOIC
ISL6160CB-T IC CTRLR BULK/AUXILIARY 14-SOIC
ISL6161CB-T IC CTRLR PWR DISTRIB DUAL 14SOIC
相關代理商/技術參數
參數描述
IRU3137 制造商:IRF 制造商全稱:International Rectifier 功能描述:8-PIN SYNCHRONOUS PWM CONTROLLER
IRU3137CS 制造商:IRF 制造商全稱:International Rectifier 功能描述:8-PIN SYNCHRONOUS PWM CONTROLLER
IRU3137CSTR 功能描述:IC REG CTRLR BUCK PWM VM 8-SOIC RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標準包裝:4,000 系列:- PWM 型:電壓模式 輸出數:1 頻率 - 最大:1.5MHz 占空比:66.7% 電源電壓:4.75 V ~ 5.25 V 降壓:是 升壓:無 回掃:無 反相:無 倍增器:無 除法器:無 Cuk:無 隔離:無 工作溫度:-40°C ~ 85°C 封裝/外殼:40-VFQFN 裸露焊盤 包裝:帶卷 (TR)
IRU3137CSTRPBF 功能描述:IC REG CTRLR BUCK PWM VM 8-SOIC RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標準包裝:4,000 系列:- PWM 型:電壓模式 輸出數:1 頻率 - 最大:1.5MHz 占空比:66.7% 電源電壓:4.75 V ~ 5.25 V 降壓:是 升壓:無 回掃:無 反相:無 倍增器:無 除法器:無 Cuk:無 隔離:無 工作溫度:-40°C ~ 85°C 封裝/外殼:40-VFQFN 裸露焊盤 包裝:帶卷 (TR)
IRU3138 制造商:IRF 制造商全稱:International Rectifier 功能描述:SYNCHRONOUS PWM CONTROLLER FOR TERMINATION POWER SUPPLY APPLICATIONS