MLX83202 Datasheet, PDF (29/35 Pages) Melexis Microelectronic Systems – Automotive NFET pre-drivers

MLX83202/MLX83203
Automotive NFET pre-drivers
8.9 100% PWM with bootstrap
A current is drawn from the CP bootstrap pin to the phase pins. This current will discharge the gate voltage
on top of any external pull down gate resistance. The below tables show some calculation examples.
bootstrap
Vreg
Qbootstr
QFET
Vgs_initial
330 nF
12 V
3960 nC
200 nC
11.4 V
bootstrap
Vreg
Qbootstr
QFET
Vgs_initial
100 nF
12 V
1200 nC
120 nC
10.9 V
Rcp_leak
leakage
On time
Qleak
Vgs_end
0.75 Mohm
15 uA
60 ms
914 nC
9.4 V
leakage
On time
Qleak
Vgs_end
15 uA
10 ms
152 nC
9.8 V
Vgs drop
2.06 V
Vgs drop
1.13 V
This gate leakage will limit the maximum state time during which 100% PWM can be applied.
3901083203
Rev 2.2
Page 29 of 35
Prelim. Data Sheet
4 Dec 2013