参数资料
| 型号： | ISL6326BIRZ |
| 厂商： | Intersil |
| 文件页数： | 23/30页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM VM 40-QFN |
| 标准包装： | 50 |
| PWM 型： | 电压模式 |
| 输出数： | 1 |
| 频率 - 最大： | 275kHz |
| 占空比： | 25% |
| 电源电压： | 4.75 V ~ 5.25 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： | -40°C ~ 85°C |
| 封装/外壳： | 40-VFQFN 裸露焊盘 |
| 包装： | 管件 |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页当前第23页第24页第25页第26页第27页第28页第29页第30页
ISL6326B
Temperature Compensation
ISL6326B supports inductor DCR sensing, or resistive
sensing techniques. The inductor DCR has a positive
temperature coefficient, which is about +0.38%/°C. Since the
voltage across inductor is sensed for the output current
information, the sensed current has the same positive
temperature coefficient as the inductor DCR.
In order to obtain the correct current information, there
should be a way to correct the temperature impact on the
current sense component. ISL6326B provides two methods:
integrated temperature compensation and external
temperature compensation.
Integrated Temperature Compensation
When the TCOMP voltage is equal or greater than VCC/15,
ISL6326B will utilize the voltage at TM and TCOMP pins to
compensate the temperature impact on the sensed current.
The block diagram of this function is shown in Figure 14.
component. The TCOMP pin voltage can be utilized to
correct the temperature difference between NTC and the
current sense component. When a different NTC type or
different voltage divider is used for the TM function, the
TCOMP voltage can also be used to compensate for the
difference between the recommended TM voltage curve in
Figure 13 and that of the actual design. According to the
VCC voltage, ISL6326B converts the TCOMP pin voltage to
a 4-bit TCOMP digital signal as TCOMP factor N.
The TCOMP factor N is an integer between 0 and 15. The
integrated temperature compensation function is disabled for
N = 0. For N = 4, the NTC temperature is equal to the
temperature of the current sense component. For N < 4, the
NTC is hotter than the current sense component. The NTC is
cooler than the current sense component for N > 4. When
N > 4, the larger TCOMP factor N, the larger the difference
between the NTC temperature and the temperature of the
current sense component.
ISL6326B multiplexes the TCOMP factor N with the TM
digital signal to obtain the adjustment gain to compensate
V CC
I sen4
the temperature impact on the sensed channel current. The
compensated channel current signal is used for droop and
o c
R TM1
TM
R NTC
Non-linear
A/D
Channel current
sense
I 4 I 3 I 2
I 1
I sen3
I sen2
I sen1
overcurrent protection functions.
Design Procedure
1. Properly choose the voltage divider for the TM pin to
match the TM voltage vs temperature curve with the
recommended curve in Figure 12.
V CC
R TC1
TCOMP
R TC2
D/A
4-bit
A/D
k i
Droop &
Over current protection
2. Run the actual board under the full load and the desired
cooling condition.
3. After the board reaches the thermal steady state, record
the temperature (T CSC ) of the current sense component
(inductor or MOSFET) and the voltage at TM and VCC
pins.
4. Use the following equation to calculate the resistance of
the TM NTC, and find out the corresponding NTC
temperature T NTC from the NTC datasheet.
) = --------------------------------
FIGURE 14. BLOCK DIAGRAM OF INTEGRATED
TEMPERATURE COMPENSATION
R NTC ( T
NTC
V TM xR TM1
V CC – V TM
(EQ. 21)
5. Use the following equation to calculate the TCOMP
When the TM NTC is placed close to the current sense
factor N:
209x ( T CSC – T
N = -------------------------------------------------------- + 4
component (inductor), the temperature of the NTC will track
the temperature of the current sense component. Therefore
the TM voltage can be utilized to obtain the temperature of
NTC
3xT NTC + 400
)
(EQ. 22)
NxR TC1
R TC2 = -----------------------
the current sense component.
Based on VCC voltage, ISL6326B converts the TM pin
voltage to a 6-bit TM digital signal for temperature
compensation. With the non-linear A/D converter of
ISL6326B, the TM digital signal is linearly proportional to the
NTC temperature. For accurate temperature compensation,
the ratio of the TM voltage to the NTC temperature of the
practical design should be similar to that in Figure 12.
Depending on the location of the NTC and the airflow, the
NTC may be cooler or hotter than the current sense
23
6. Choose an integral number close to the above result for
the TCOMP factor. If this factor is higher than 15, use
N = 15. If it is less than 1, use N = 1.
7. Choose the pull-up resistor R TC1 (typical 10k Ω );
8. If N = 15, do not need the pull-down resistor R TC2 ,
otherwise obtain R TC2 by the following equation:
(EQ. 23)
15 – N
9. Run the actual board under full load again with the proper
resistors connected to the TCOMP pin.
FN9286.0
April 21, 2006
相关PDF资料 |
PDF描述 |
|---|---|
| ISL6326IRZ | IC REG CTRLR BUCK PWM VM 40-QFN |
| ISL6327AIRZ | IC REG CTRLR BUCK PWM 48-QFN |
| ISL6327IRZ | IC REG CTRLR BUCK PWM 48-QFN |
| ISL6328AIRZ | IC VOLTAGE REGULATOR |
| ISL6328IRZ | IC CTRLR PWM SYNC BUCK DL 48QFN |
相关代理商/技术参数 |
参数描述 |
|---|---|
| ISL6326BIRZ-T | 功能描述:电流型 PWM 控制器 W/ANNEAL 4-PHS VR11 CNTRLR IND RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14 |
| ISL6326CRZ | 功能描述:电流型 PWM 控制器 W/ANNEAL 4-PHS VR11 CNTRLR COM RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14 |
| ISL6326CRZ-T | 功能描述:电流型 PWM 控制器 W/ANNEAL 4-PHS VR11 CNTRLR COM RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14 |
| ISL6326CRZ-TR5453 | 制造商:Intersil Corporation 功能描述:STD. ISL6326CRZ-T W/GOLD BOND WIRE ONLY - Tape and Reel |
| ISL6326IRZ | 功能描述:电流型 PWM 控制器 W/ANNEAL 4-PHS VR11 CNTRLR IND RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14 |
发布紧急采购，3分钟左右您将得到回复。