參數(shù)資料
型號: MAX472CPA
廠商: Maxim Integrated Products
文件頁數(shù): 11/13頁
文件大?。?/td> 0K
描述: IC AMP CURR-SENSE HI-SIDE 8-DIP
標準包裝: 50
放大器類型: 電流檢測
電路數(shù): 1
電流 - 輸入偏壓: 20µA
電壓 - 輸入偏移: 120µV
電流 - 電源: 20µA
電流 - 輸出 / 通道: 1.5mA
電壓 - 電源,單路/雙路(±): 3 V ~ 36 V
工作溫度: 0°C ~ 70°C
安裝類型: 通孔
封裝/外殼: 8-DIP(0.300",7.62mm)
供應商設備封裝: 8-PDIP
包裝: 管件
其它名稱: Q1142329
MAX471/MAX472
_______________Detailed Description
The MAX471 and MAX472 current-sense amplifier’s
unique topology allows a simple design to accurately
monitor current flow. The MAX471/MAX472 contain two
amplifiers operating as shown in Figures 1 and 2. The
battery/load current flows from RS+ to RS- (or vice
versa) through RSENSE. Current flows through either
RG1 and Q1 or RG2 and Q2, depending on the sense-
resistor current direction. Internal circuitry, not shown in
Figures 1 and 2, prevents Q1 and Q2 from turning on at
the same time. The MAX472 is identical to the
MAX471, except that RSENSE and gain-setting resistors
RG1 and RG2 are external (Figure 2).
To analyze the circuit of Figure 1, assume that current
flows from RS+ to RS- and that OUT is connected to
GND through a resistor. In this case, amplifier A1 is
active and output current IOUT flows from the emitter of
Q1. Since no current flows through RG2 (Q2 is off), the
negative input of A1 is equal to VSOURCE - (ILOAD x
RSENSE). The open-loop gain of A1 forces its positive
input to essentially the same level as the negative input.
Therefore, the drop across RG1 equals I LOAD x
RSENSE. Then, since IOUT flows through Q1 and RG
(ignoring the extremely low base currents), IOUT x RG1
= ILOAD x RSENSE, or:
IOUT = (ILOAD x RSENSE) / RG1
Current Output
The output voltage equation for the MAX471/MAX472 is
given below. In the MAX471, the current-gain ratio has
been preset to 500A/A so that an output resistor
(ROUT) of 2k
yields 1V/A for a full-scale value of +3V
at ±3A. Other full-scale voltages can be set with differ-
ent ROUT values, but the output voltage can be no
greater than VRS+ - 1.5V for the MAX471 or VRG_ - 1.5V
for the MAX472.
VOUT = (RSENSE x ROUT x ILOAD) / RG
where VOUT = the desired full-scale output voltage,
ILOAD = the full-scale current being sensed, RSENSE =
the current-sense resistor, ROUT = the voltage-setting
resistor, and RG = the gain-setting resistor (RG = RG1
= RG2).
The above equation can be modified to determine the
ROUT required for a particular full-scale range:
ROUT = (VOUT x RG) / (ILOAD x RSENSE)
For the MAX471, this reduces to:
ROUT = VOUT / (ILOAD x 500A/A)
OUT is a high-impedance current-source output that
can be connected to other MAX471/MAX472 OUT pins
Precision, High-Side
Current-Sense Amplifiers
6
_______________________________________________________________________________________
______________________________________________________________Pin Description
Load side of the internal current-sense resistor. The “-” indicates direction of flow for SIGN
output only. Connect pins 6 and 7 together at the package.
RS-
6, 7
Gain Resistor. Connect to load side of current-sense resistor through the gain resistor.
RG2
Power input for MAX472. Connect to sense resistor (RSENSE) junction with RG1.
VCC
Current output that is proportional to the magnitude of the sensed current flowing through
RSENSE. A 2k resistor from this pin to ground will result in a voltage equal to 1V/Amp of
sensed current in the MAX471.
OUT
8
Gain Resistor. Connect to battery side of current-sense resistor through the gain resistor.
RG1
Ground or Battery Negative Terminal
GND
4
An open-collector logic output. For the MAX471, a low level indicates current is flowing from
RS- to RS+. For the MAX472, a low level indicates a negative VSENSE (see Figure 2). SIGN is
high impedance when SHDN is high. Leave open if SIGN is not needed.
SIGN
5
No Connect—no internal connection
N.C.
Battery (or power) side of the internal current-sense resistor. The “+” indicates direction of
flow for SIGN output only. Connect pins 2 and 3 together at the package.
RS+
2, 3
Shutdown. Connect to ground for normal operation. When high, supply current is
less than 5A.
SHDN
1
FUNCTION
MAX471
NAME
6
7
8
3
4
5
2
PIN
1
MAX472
相關PDF資料
PDF描述
MAX479CPD IC OPAMP SNGL SUP QUAD 14-DIP
RMCF2010JT820R RES 820 OHM 3/4W 5% 2010 SMD
MAX475CSD IC OPAMP QUAD 10MHZ 14-SOIC
2-534237-3 CONN RCPT 25POS .100 VERT
MAX474CSA IC OPAMP DUAL 10MHZ 8-SOIC
相關代理商/技術參數(shù)
參數(shù)描述
MAX472CPA+ 功能描述:特殊用途放大器 RoHS:否 制造商:Texas Instruments 通道數(shù)量:Single 共模抑制比(最小值): 輸入補償電壓: 工作電源電壓:3 V to 5.5 V 電源電流:5 mA 最大功率耗散: 最大工作溫度:+ 70 C 最小工作溫度:- 40 C 安裝風格:SMD/SMT 封裝 / 箱體:QFN-20 封裝:Reel
MAX472CSA 功能描述:特殊用途放大器 RoHS:否 制造商:Texas Instruments 通道數(shù)量:Single 共模抑制比(最小值): 輸入補償電壓: 工作電源電壓:3 V to 5.5 V 電源電流:5 mA 最大功率耗散: 最大工作溫度:+ 70 C 最小工作溫度:- 40 C 安裝風格:SMD/SMT 封裝 / 箱體:QFN-20 封裝:Reel
MAX472CSA+ 功能描述:特殊用途放大器 RoHS:否 制造商:Texas Instruments 通道數(shù)量:Single 共模抑制比(最小值): 輸入補償電壓: 工作電源電壓:3 V to 5.5 V 電源電流:5 mA 最大功率耗散: 最大工作溫度:+ 70 C 最小工作溫度:- 40 C 安裝風格:SMD/SMT 封裝 / 箱體:QFN-20 封裝:Reel
MAX472CSA+T 功能描述:特殊用途放大器 RoHS:否 制造商:Texas Instruments 通道數(shù)量:Single 共模抑制比(最小值): 輸入補償電壓: 工作電源電壓:3 V to 5.5 V 電源電流:5 mA 最大功率耗散: 最大工作溫度:+ 70 C 最小工作溫度:- 40 C 安裝風格:SMD/SMT 封裝 / 箱體:QFN-20 封裝:Reel
MAX472CSA-T 功能描述:特殊用途放大器 RoHS:否 制造商:Texas Instruments 通道數(shù)量:Single 共模抑制比(最小值): 輸入補償電壓: 工作電源電壓:3 V to 5.5 V 電源電流:5 mA 最大功率耗散: 最大工作溫度:+ 70 C 最小工作溫度:- 40 C 安裝風格:SMD/SMT 封裝 / 箱體:QFN-20 封裝:Reel