UC3845DR2G ON Semiconductor, UC3845DR2G Datasheet - Page 6
![IC CTRLR CURRENT MODE HP 14SOIC](/photos/6/57/65767/14-soic_751a_sml.jpg)
UC3845DR2G
Manufacturer Part Number
UC3845DR2G
Description
IC CTRLR CURRENT MODE HP 14SOIC
Manufacturer
ON Semiconductor
Type
High Performance Current Mode Controllersr
Datasheet
1.UC3845DR2.pdf
(16 pages)
Specifications of UC3845DR2G
Pwm Type
Current Mode
Number Of Outputs
1
Frequency - Max
60kHz
Duty Cycle
50%
Voltage - Supply
8.2 V ~ 25 V
Buck
No
Boost
Yes
Flyback
Yes
Inverting
Yes
Doubler
No
Divider
No
Cuk
No
Isolated
Yes
Operating Temperature
0°C ~ 70°C
Package / Case
14-SOIC (3.9mm Width), 14-SOL
Frequency-max
60kHz
Output Voltage Range
4.9 V to 5.1 V
Input Voltage Range
30 V
Operating Temperature Range
0 C to + 70 C
Mounting Style
SMD/SMT
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Other names
UC3845DR2GOS
PIN FUNCTION DESCRIPTION
8−Pin
1
2
3
4
5
6
7
8
−
−
−
−
Pin
2,4,6,13
14−Pin
Figure 14. Output Cross Conduction
10
12
14
11
1
3
5
7
−
8
9
Compensation
Current Sense
Power Ground
Feedback
Function
Voltage
Output
R
GND
GND
100 ns/DIV
V
V
NC
T
V
CC
ref
/C
C
T
This pin is Error Amplifier output and is made available for loop compensation.
This is the inverting input of the Error Amplifier. It is normally connected to the switching
power supply output through a resistor divider.
A voltage proportional to inductor current is connected to this input. The PWM uses this
information to terminate the output switch conduction.
The Oscillator frequency and maximum Output duty cycle are programmed by connecting
resistor R
This pin is combined control circuitry and power ground (8−pin package only).
This output directly drives the gate of a power MOSFET. Peak currents up to 1.0 A are
sourced and sunk by this pin. The output switches at one−half the oscillator frequency.
This pin is the positive supply of the control IC.
This is the reference output. It provides charging current for capacitor C
This pin is a separate power ground return (14−pin package only) that is connected back to
the power source. It is used to reduce the effects of switching transient noise on the control
circuitry.
The Output high state (V
With a separate power source connection, it can reduce the effects of switching transient
noise on the control circuitry.
This pin is the control circuitry ground return (14−pin package only) and is connected to back
to the power source ground.
No connection (14−pin package only). These pins are not internally connected.
V
C
T
A
CC
L
T
= 255C
= 15 pF
to V
= 30 V
http://onsemi.com
ref
and capacitor C
6
OH
) is set by the voltage applied to this pin (14−pin package only).
25
20
15
10
5
0
0
T
to ground. Operation to 1.0 MHz is possible.
Description
Figure 15. Supply Current versus
10
V
CC
Supply Voltage
, SUPPLY VOLTAGE (V)
20
T
through resistor R
R
C
V
I
T
Sense
30
A
FB
T
T
= 255C
= 10 k
= 3.3 nF
= 0 V
= 0 V
40
T
.