BTF50060-1TEA_11 Datasheet, PDF (20/38 Pages) Infineon Technologies AG – Smart High-Side Power Switch, One Channel

BTF50060-1TEA
Functional Description
5.4
Diagnosis Functions
For diagnosis purpose, the BTF50060-1TEA provides an enhanced analog sense signal at the pin IS. For an
overview of the diagnosis functions, you may have a look at Figure 15 “Diagram of Diagnosis & Protection
block”.
5.4.1 Sense Output
The current sense output is a current source driving a signal I_IS proportional to the load current (see Equation (5))
as long as no “hard” failure mode occurs (short circuit to GND / over temperature) and V_SIS = V_S - V_IS > 3V. It is
activated and deactivated by the input signal. Usually, in the application a pull-down resistor R_IS is connected
between the current sense pin IS and GND pin. A typical value is R_IS = 1.0 kΩ. Figure 46 shows a simplified
application setup.
Table 5 is giving a quick reference for the logic / analog state of the IS pin during device operation.
In case a short circuit or an over temperature condition is detected, the sense output is supplying a fault signal
I_IS(fault). The fault signal is reset by an input signal being LOW for t > t_RESET. As long as an open load, short-to-V_S
or inverse operation is detected while the device is in OFF state, the sense output also supplies the fault signal
I_IS(fault). The timings and logic of the IS pin are described in Figure 21. During output turning ON or OFF, the sense
signal is invalid. Please note: if the devices logic is inactive, e.g. because the IN signal was LOW for t > t_RESET, the
logic of the device needs a wake-up time of t_wake for activating the sense output in addition to the current sense
settling time for turn ON t_sIS(ON). See also Figure 11.
Table 5 Truth Table for Sense Signal
Operation mode
Input level
Output level
Normal operation
HIGH¹⁾
LOW ²⁾ for t < t_RESET
LOW for t > t_RESET
V_OUT = V_S - R_DS(ON) * I_L
V_OUT ~ GND
(V_OUT < V_OUT(OLL))
Inverse operation
HIGH
V_OUT > V_S
LOW for t < t_RESET
LOW for t > t_RESET
After short circuit to GND or HIGH or
over temperature detection LOW for t < t_RESET
V_OUT ~ GND
LOW for t > t_RESET
Short circuit to V_S
HIGH
V_OUT = V_S
LOW for t < t_RESET
LOW for t > t_RESET
Open load
HIGH
LOW for t < t_RESET
V_OUT = V_S
V_OUT
>
V 4)
OUT(OLH)
1) HIGH: V_IN = V_IN(H)
2) LOW: V_IN = V_IN(L)
3) Z: High impedance
LOW for t > t_RESET
4) Can be achieved e.g. with external pull up resistor R_OL, see Figure 46.
Sense output
I_IS = (I_L / k_IS) + I_IS(OFFSET)
I_IS = I_IS(OFFSET)
Z³⁾ (I_IS = I_IS(LL))
I_IS ≤ I_IS(OFFSET)
I_IS = I_IS(OFFSET)
I_IS = I_IS(FAULT)
I_IS = I_IS(FAULT)
Z (I_IS = I_IS(LL))
I_IS ≤ I_IS(OFFSET)
I_IS = I_IS(OFFSET)
I_IS = I_IS(FAULT)
I_IS ≤ I_IS(OFFSET)
I_IS = I_IS(OFFSET)
I_IS = I_IS(FAULT)
Datasheet
Speed PROFET^TM
20
Rev. 1.2, 2011-09-01