TLE7184F_15 Datasheet, PDF (16/38 Pages) Infineon Technologies AG – System IC for B6 motor drives

TLE7184F
Shunt Signal Conditioning
6
Shunt Signal Conditioning
The TLE7184F incorporates a fast and precise operational amplifier for conditioning and amplification of the
current sense shunt signal. The gain of the OpAmp is adjustable by external resistors within a range higher than 5.
The usage of higher gains in the application might be limited by required settling time and band width.
It is recommended to apply a small offset to the OpAmp, to avoid operation close to the lower rail at low currents.
The output of the OpAmp ISO is not short-circuit proof.
In addition to the integrated operational amplifier, the TLE7184F incorporates a comparator to detect over current
situations. The output voltage V_ISO is compared to a reference voltage V_OCTH close to the upper rail of the 5V
OpAmp supply (VDD). If V_ISO reaches this level an error is set.
V_DD
R_fb2
V_DD
R_S1
ISP
ASIC
+
internal
ISO
µC
R_shunt
-
RS2
ISN
+
R_fb3
ERR
- _VOCTH
330pF
external
R_fb2 R_fb3 = R_fb1
R_fb1
fc < 1 Mhz
Figure 5 Shunt Signal Conditioning Block Diagram and Over Current Limitation
Over current shut down see Chapter 9.2.13.
6.1
Electrical Characteristics
Electrical Characteristics - Current sense signal conditioning
V_S = 6.0 to 33 V, T_j = -40 °C to +150 °C, gain = 5 to 75, all voltages with respect to ground, positive current flowing
into pin (unless otherwise specified)¹⁾
Pos. Parameter
Symbol
Limit Values
Unit Conditions
Min. Typ. Max.
6.1.1 Series resistors
R_S
100 500 1000 Ω
6.1.2 Feedback resistor
R_fb
2000 7500 –
Ω
6.1.3 Resistor ratio (gain ratio),
R_fb/RS
5
–
–
–
max. gain limited by settling time
–
–
R_L>3kΩ
6.1.4
6.1.5
Input differential voltage (ISP - ISN) V_IDR
Input voltage (Both Inputs - GND) V_LL
(ISP - GND) or (ISN -GND)
-800 –
-800 –
800 mV –
2000 mV –
6.1.6
6.1.7
Input offset voltage of the I-DC link V_IO
OpAmp, including temperature drift
Input bias current (ISN,ISP to
I_IB
GND)
–
–
-300 –
+/-2 mV R_S=500Ω; V_CM=0V;
V_ISO=1.65V;
–
µA
V_CM=0V; V_ISO=open
Data Sheet
16
Rev. 1.1, 2011-04-08