UC2842AD ON Semiconductor, UC2842AD Datasheet - Page 12
![Other Power Management 52kHz 1A Current PWM](/photos/16/10/161082/soic-14_sml.jpg)
UC2842AD
Manufacturer Part Number
UC2842AD
Description
Other Power Management 52kHz 1A Current PWM
Manufacturer
ON Semiconductor
Type
High Performance Current Mode Controllersr
Datasheet
1.UC3843AN2.pdf
(18 pages)
Specifications of UC2842AD
Output Voltage Range
4.95 V to 5.05 V
Input Voltage Range
30 V
Operating Temperature Range
- 25 C to + 85 C
Mounting Style
SMD/SMT
Package / Case
SOIC-14
Lead Free Status / Rohs Status
Lead free / RoHS Compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Part Number:
UC2842AD
Manufacturer:
TI
Quantity:
20 000
Company:
Part Number:
UC2842AD8
Manufacturer:
TI
Quantity:
13 178
Part Number:
UC2842AD8
Manufacturer:
TI/德州仪器
Quantity:
20 000
Company:
Part Number:
UC2842AD8TR
Manufacturer:
VISHAY
Quantity:
30 000
Part Number:
UC2842AD8TR
Manufacturer:
TI/德州仪器
Quantity:
20 000
Company:
Part Number:
UC2842AD8TRG4
Manufacturer:
TI
Quantity:
14 033
Part Number:
UC2842ADR
Manufacturer:
UC/TI
Quantity:
20 000
Part Number:
UC2842ADTR
Manufacturer:
TI/德州仪器
Quantity:
20 000
V
Clamp
C
R2
R1
External
Sync
Input
8(14)
R2
R1
4(7)
2(3)
1(1)
=
Figure 23. Adjustable Reduction of Clamp Level
Figure 21. External Clock Synchronization
8(14)
Figure 25. Adjustable Buffered Reduction of
V
4(7)
2(3)
1(1)
MPSA63
Clamp
R
R
The diode clamp is required if the Sync amplitude is large enough to
cause the bottom side of CT to go more than 300 mV below ground.
1.67
2
1
0.01
+
−
=
+ 1
EA
R
R
+
−
R
R
Clamp Level with Soft−Start
+
EA
+ 0.33 x 10 − 3
1.67
2
1
R
R
Osc
1.0mA
Bias
+
C
+ 1
R
47
T
Osc
1.0mA
T
Bias
2R
R
V
2R
ref
8(14)
I
4(7)
2(3)
1(1)
R
pk(max)
5(9)
V
t
Clamp
Softstart
R
5(9)
−
R
+
1.0V
V
1
=
5.0V
1
Clamp
+ R
−
R
+
1.0V
−
+
5.0V
UC3842A, UC3843A, UC2842A, UC2843A
+
−
2
+
−
ref
2
= − In
VClamp
−
+
EA
+
−
RS
Comp/Latch
R
R
ref
S
R
Comp/Latch
+
Q
Osc
S
R
Bias
Q
I
pk(max)
1 −
Where: 0 ≤ V
+
−
2R
Where: 0 ≤ V
+
−
R
+
3V
7(12)
−
=
+
V
Clamp
7(12)
−
C
5(9)
VClamp
Clamp
http://onsemi.com
RS
Clamp
V
CC
7(11)
6(10)
5(8)
3(5)
V
C
CC
≤ 1.0 V
7(11)
6(10)
5(8)
3(5)
≤ 1.0 V
R
R
1
1
+ R
R
12
2
Q1
Q1
R
2
V
R
V
S
in
f =
S
in
R
R
C
Virtually lossless current sensing can be achieved with the implementation of a
SENSEFET power switch. For proper operation during over current conditions, a
reduction of the I
B
(R
A
6
5
2
A
−
+
1.44
+ 2R
Figure 26. Current Sensing Power MOSFET
Figure 22. External Duty Cycle Clamp and
5.0V
−
+
+
−
B
ref
8
5.0k
1
)C
5.0k
+
−
+
−
Comp/Latch
C
S
R
pk(max)
MC1455
Q
Multi Unit Synchronization
1.0M
R
S
D
Control CIrcuitry
8(14)
Q
max
4(7)
2(3)
1(1)
+
To Pin (9)
4
−
t
Ground:
clamp level must be implemented. Refer to Figures 23 and 25.
Soft−Start
Figure 24. Soft−Start Circuit
=
+
(12)
−
R
A
3600C in mF
R
+ 2R
+
−
B
EA
7
R
R
3
V
B
CC
(11)
(10)
(8)
(5)
+
Osc
1.0mA
Bias
G
1/4 W
R
8(14)
M
S
2R
D
4(7)
2(3)
1(1)
R
SENSEFET
V
To
Additional
UCX84XA’s
in
K
To Input Source
Power Ground
S
5(9)
If: SENSEFET = MTP10N10M
Return
V
Pin
+
−
−
+
1.0V
5.0V
Then: V
EA
5 =
R
R
−
+
+
−
+
ref
Osc
R
r
pin
Bias
S
DM(on)
R
S
R
I
S
5 = 0.075 I
pk
Q
= 200
2R
r
+ R
DS(on)
R
S
5(9)
pk