DESCRIPTION
The UCC38083/4/5/6 is a family of BiCMOS pulse
widthmodulation (PWM) controllers for dc-to-dc
or off-linefixed-frequency current-mode switching
powersupplies. The dual output stages are configured
for thepush-pull topology. Both outputs switch at half
theoscillator frequency using a toggle flip-flop.
The deadtime between the two outputs is typically 110 ns,
limitingeach output’s duty cycle to less than 50%.
The new UCC3808x family is based on the UCC3808Aarchitecture.
The major differences include the additionof a programmable
slope compensation ramp to the CSsignal and the removal of
the error amplifier. The currentflowing out of the ISET pin
through an external resistoris monitored internally to set
the magnitude of the slopeV OUTcompensation function.
This device also includes aninternal discharge transistor
from the CS pin to ground,which is activated at each clock
cycle after the pulse isterminated. This discharges any filter
capacitance onthe CS pin during each cycle and helps minimize
filtercapacitor values and current sense delay.
The UCC38083 and the UCC38084 devices have atypical soft-start
interval time of 3.5 ms while theUCC38085 and the UCC38086 has
less than 100μsforapplications where internal soft-start is not desired.
The UCC38083 and the UCC38085 devices have theturn-on/off thresholds
of 12.5 V / 8.3 V, while theUCC38084 and the UCC38086 has the
turn-on/offthresholds of 4.3 V / 4.1 V. Each device is offered
in 8-pinTSSOP (PW), 8-pin SOIC (D) and 8-pin PDIP (P)packages
FEATURES
Programmable Slope Compensation
Internal Soft-Start on the UCC38083/4
Cycle-by-Cycle Current Limiting
Low Start-Up Current of 120μAand 1.5 mATypical Run Current
Single External Component OscillatorProgrammable from 50 kHz to 1 MHz
High-Current Totem-Pole Dual Output StageDrives Push-Pull Configuration
with 1-A Sinkand 0.5-A Source Capability
Current Sense Discharge Transistor to Improve Dynamic Response
Internally Trimmed Bandgap Reference
Undervoltage Lockout with Hysteresis
APPLICATIONS
High-Efficiency Switch-Mode Power Supplies
Telecom dc-to-dc Converters
Point-of-Load or Point-of-Use Power Modules
Low-Cost Push-Pull and Half-Bridge Applications
BASIC APPLICATION
Typical application
Part No Temp(0℃） Package
UCC38084D 0 to 70 SOIC (D) | 8
UCC38084DG4 0 to 70 SOIC (D) | 8
UCC38084DR 0 to 70 SOIC (D) | 8
UCC38084DRG4 0 to 70 SOIC (D) | 8
UCC38084P 0 to 70 PDIP (P) | 8
UCC38084PG4 0 to 70 PDIP (P) | 8
UCC38084PW 0 to 70 TSSOP (PW) | 8
UCC38084PWR 0 to 70 TSSOP (PW) | 8
UCC38084PWRG4 0 to 70 TSSOP (PW) | 8
FROM: Company Name: Aunytor Electronic (HK) Co.,Ltd
Contact Person: liao
Skype: Aunytor
Email: 2885745253@qq.com