BTF50060-1TEA_11 Datasheet, PDF (13/38 Pages) Infineon Technologies AG – Smart High-Side Power Switch, One Channel

BTF50060-1TEA
Functional Description
V_IN
V_OUT
t > t_RESET
t_RESET
t_wake+t_ON
t < t_RESET
t_ON ^t
I_IS
t_wake+t_sIS(ON)
t_sIS(ON)
t
Figure 11 Wake up timing
I_IS(OFFSET)
t
wa ke- u p. e mf
5.1.2
Switching an Inductive Load - Infineon^® SMART CLAMPING
When switching OFF inductive loads with no path for load current freewheeling available, the output voltage V_OUT
drops below ground potential due to the involved inductance ( -di_L/dt = -v_L/L ; -V_OUT ≅ -V_L ). To prevent the
destruction of the device due to high voltages, there is a voltage clamp mechanism implemented that keeps the
negative output voltage at a certain level (-V_OUT=V_S-V_SD(CL)). Please refer to Figure 1 and Figure 12 for details.
V _{O UT}
V_S
ON
OFF
V _SD(CL)
t
I_L
t
S wit ch in g In d u cta n ce.e mf
Figure 12 Switching an inductance
Nevertheless, the energy capability of the device is limited because the energy is converted into heat. That’s why
the maximum allowed load inductance is limited as well. Please see Figure 4 for limitations of energy and load
inductance.
For calculationg the demagnization energy, Equation (1) may be used:
E_A
=
V_SD(CL)
×
--^L---
R_L
×
V_-----S----–_-----V_{----S---D---(--C---L---)}
R_L
×
ln
⎛
⎝
1
+
-_V----_S---^R_D----₍-^L-_C---^×_L---₎--^I-_–--^L---_V-----_S-_⎠⎞
+
I_L
(1)
The equation can be simplified under the assumption of R_L = 0 Ω to:
E_A
=
1--
2
×
L
×
I_L²
×
-------^V----^S---^D----⁽-^C----^L--⁾-------
V_SD(CL) – V_S
(2)
The BTF50060-1TEA provides Infineon^® SMART CLAMPING functionality. To optimize the energy capability for
single and parallel operation, the clamp voltage V_SD(CL) increases over the junction temperature T_j and load current
I_L. Figure 33 shows the dependency from T_j for the typical V_SD(CL). Please refer also to Figure 15.
Datasheet
Speed PROFET^TM
13
Rev. 1.2, 2011-09-01