WCA_BC846_TMOT_20080821

V3
+ -
S2
+
V
V1 = 0 V2 = 4000 TD = 100n TR = 0.1n TF = 0.1n PW = 300n PER = 200m
V2
V1 = 0 V2 = 10 TD = 100n TR = 0.1n TF = 0.1n PW = 200n PER = 200m
V1
-
S VOFF = 0.0V VON = 1.0V
age is negtive, the max, voltage of ESD capacitor will be bigger than -300V passed
can change from 0805 to 0603
Unit Watt
can change from 1206 to 0603
Unit Watt
CPURST
VCC
*
R 6045 R 6045
so the PULLUP resister have to bigger than 2
R
PU
imit
VBE ( on ) / R 6049
set R4=7.5R the current limit is below 100mA but BC846 max allow current is 100mA so set a safe zone
pulse 3A Verification
voltage on BC846(V) -0.02
Max voltage limit(V) 6.00
result passed
peak power pulse 3A Verification dissipation R6044 R6049 2.6732W 0.0000W
Il imit VBE ( on ) / R 6049
3. Check when ESD happens
ESD simulation when ESD test voltage is positive
S1
+ +
passed
when ESD test voltage is negative
S1
+ +
9. Rsense power dissipation
R6045,R6047 Requirement Resistance of R6045 0603 0.059 0.003
Normal R6049,R6043 Requirement 0.0000 40deg 0.100 Normal R6044 Requirement 0.0258 40deg 0.125
pulse 1 Verification
voltage on BC846(V) -1.33
Max voltage limit(V) 6.00 Pmax/Watt @ 40 ° C & pulse time:2ms 2.80W 1.90W
result passed
pulse 1 Verification R6044 R6049
Note: the simulation ignore the other parameter influence, like clamp voltage. And assume that the max. ESD votlage of ca
When the test voltage is positive, the max, voltage of ESD capacitor When will be the smaller test voltage than 300V is negtive, the max, voltage of ES result passed result passed unit Watt Watt
V3
+ -
+
-
0
S VOFF = 0.0V VON = 1.0V R1 330 C1 150p
0
150V
0
TD = 300n TR = 0.1n TF = 0.1n PW = 5u PER = 200m
S VOFF = 0.0V VON = 1.0V R1 330 C1 150p
CST 4.7n
0
#REF! 2.ISO pulse 2
1
1
pulse 2 simulation curve
0V
0V
-429.6e-21V 4.292e-21V 0V 0V
voltage on BC846 T6042
R6044(green),R6049(red) transicent power dissipation at pulse 3A
0
0
V1 = 0 V2 = -4000 TD = 100n TR = 0.1n TF = 0.1n PW = 300n PER = 200m S2
V2
0
-
0
S VOFF = 0.0V VON = 1.0V R1 330 C1 150p
CST 4.7n
0
V1 = 0 V2 = 10 TD = 300n TR = 0.1n TF = 0.1n PW = 5u PER = 200m
1 * R * C
min Requirement Signal accuracy PWM output control
max 50.000 3.000
unit us us
output up time delay
2. Transfer function check
Control of BC846 CPU high threshold CPU low threshold ON voltage of BC846 ON STATE OUT VOLTAGE,PU10 k OFF STATE OUT VOLTAGE,PU10 ON voltage of BC846 in reset min 4.100 0.400 0.770 0.025 9.000 0.478 max unit V V V V V V
voltage on pulse 2 Verification BC846(V) 3.56
Max voltage limit(V) 65.00
result passed
Pmax/Watt @ peak power pulse 2 Verification 40 ° C & pulse dissipation time:50us R6044 R6049 0.7432W 0.0000W 3.80W 2.00W
Load Dump 0.0742 Watt
SCB 0.0000
10. Reverse battery
建议将负载接在UBR上实现反相保护功能。
passed
11. ISO pulse Verification
1.ISO pulse 1
V1 = 0 V2 = -113.5 TD = 0 TR = 1u TF = 1.999m PW = 0.001u PER = 5 R6048 V3
V
R6044 10k
0
Q1 BC846BW/PLP C0011
V1 = 0 V2 = -113.5 TD = 0 TR = 1u TF = 1.999m PW = 0.001u PER = 5 R6048 V2 0Vdc Rr6045 10k 1k BC846BW/PLP Q2
V3
V
R6044 10k
peak power dissipation 1.2600W 0.0000W
result passed passed
3. ISO Pulse 3A
0Vdc
pulse 3A simulation curve
voltage on BC846 T6042
R6044(green),R6049(red) transicent power dissipation at pulse 3A
0
Q1 BC846BW/PLP C0011 47n
R609 10
0
pulse 1 simulation curve
0
0
0
0V
0V
0V
-429.6e-21V 4.292e-21V
0V
0V
0V
voltage on BC846 T6042
R6044(green),R6049(red) transicent power dissipation at pulse 3A
V1 = 0 V2 = 10 TD = 100n TR = 0.1n TF = 0.1n PW = 200n PER = 200m
V1
-
S VOFF = 0.0V VON = 1.0V
0
V1 = 0 V2 = 10 TD = 300n TR = 0.1n TF = 0.1n PW = 5u PER = 200m
result passed passed
V1 = 0 V2 = 86.5 TD = 0 TR = 5n
V3 R6044
4. ISO Pulse 3B
V1 = 0 V2 = 86.5 TD = 0 TR = 5n TF = 95n PW = 0.001n PER = 100u R6048 V2 0Vdc Rr6045 10k 1k BC846BW/PLP R609 10
Pmax/Watt @ 40 ° C & pulse time:0.1us 3.80W 2.00W
result passed passed
12. Partlist
Partlist package value partnumber R6045 0603 10K 1267360318 R6046 0603 1K 1267360301 R6047 0603 10K 1267360318 R6048 0603 1K 1267360301 R6044 0805 10K 1267360147
V2
0
CST 4.7n
= 300n = 0.1n = 0.1n = 5u R = 200m
S VOFF = 0.0V VON = 1.0V R1 330 C1 150p
CST 4.7n
0
0
0
9us
10us
ume that the max. ESD votlage of capacitor can be +/-3*100 = +/-300V
13. Draft Schematic
PWM output simulation curve
output down time delay
out ( on )
(U
b
V CE
sat
)*
R 6049 R 6044 R 6049
0.794V
when PULLUP resister is 200R ON STATE O
Jump start 0.0001 105deg 0.059 Jump start 0.0585 105deg 0.074
Starter defect 0.0000 25deg 2.000 Starter defect 0.0327 25deg 3.800
Load Dump 0.0001 Watt
SCB 0.0299
age is negative
S1
+ +
-
S VOFF = 0.0V VON = 1.0V
0
=0 = 10 = 300n = 0.1n = 0.1n = 5u R = 200m
V3
+ -
S2
+
-
0
S VOFF = 0.0V VON = 1.0V R1 330 C1 150p
0
0
V
V1 = 0 V2 = -4000 TD = 100n TR = 0.1n TF = 0.1n PW = 300n PER = 200m
0
TD = 300n TR = 0.1n TF = 0.1n PW = 5u PER = 200m
S VOFF = 0.0V VON = 1.0V R1 330 C1 150p
0
0
150V
0
100V
50V
0V 0s V(CST:2) Time 1us 2us 3us 4us 5us 6us 7us 8us 9us 10us
Calculation for BC846_TMOT
color meaning
input required requirement fullfilled requirement not fullfilled
1. Accuracy Calculation
I
BE ( o n )
f
C O

2
*

passed
passed
V
out ( on )
(U
b
V CE
sat
)*源自文库
V
CPURST
VCC
*
R
3. Current chceck
BC846 current min max unit
passed
Requirement 100.000 mA L9741 LSS load 87.714 mA current short to UB current is also limited in 34mA, so the module will not be damaged