Texas Instruments UCC3807N-3, UCC3807N-2, UCC3807N-1, UCC3807DTR-3, UCC3807DTR-1 Datasheet

Programmable Maximum Duty Cycle PWM Controller

UCC1807-1/-2/-3
UCC2807-1/-2/-3
UCC3807-1/-2/-3

FEATURES

• User Programmable
Maximum PWM
Duty Cycle

• 100µA Startup Current

• Operation to 1MHz

• Internal Full Cycle
Soft Start

• Internal Leading Edge
Blanking of Current
Sense Signal

• 1 Amp Totem Pole
Output

DESCRIPTION

The UCC3807 family of high speed, low power integrated circuits contains all of the
control and drive circuitry required for off-line and DC-to-DC fixed frequency current
mode switching power supplies with minimal external parts count.

These devices are similar to the UCC3800 family, but with the added feature of a
user programmable maximum duty cycle.Oscillator frequency and maximum duty
cycle are programmed with two resistors and a capacitor.The UCC3807 family also
features internal full cycle soft start and internal leading edge blanking of the cur­rent sense input.

The UCC3807 family offers a variety of package options, temperature range
options, and choice of critical voltage levels.The family has UVLO thresholds and
hysteresis levels for off-line and battery powered systems. Thresholds are shown in
the table below.

6/97

BLOCK DIAGRAM

Part Number Turn-on Threshold Turn-off Threshold
UCCx807-1 7.2V 6.9V
UCCx807-2 12.5V 8.3V
UCCx807-3 4.3V 4.1V

UDG-95001-1

2

UCC1807-1/-2/-3
UCC2807-1/-2/-3
UCC3807-1/-2/-3

ABSOLUTE MAXIMUM RATINGS

Supply Voltage (IDD ≤ 10mA) . . . . . . . . . . . . . . . . . . . . . . .13.5V

Supply Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30mA

OUT Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .±1A

Analog Inputs (FB, CS) . . . . . . . . . . . . .−0.3V to (VDD + 0.3V)

Power Dissipation at TA +25°C (N or J packages) . . . . . . . .1W

Power Dissipation at TA +25°C (D package) . . . . . . . . . .0.65W

Storage Temperature . . . . . . . . . . . . . . . . . . . .−65°C to +150°C

Junction Temperature . . . . . . . . . . . . . . . . . . .−65°C to +150°C

Lead Temperature (Soldering, 10 sec.) . . . . . . . . . . . . .+300°C

All currents are positive into, negative out of the specified terminal.
Consult Packaging Section of Databook for thermal limitations
and considerations of packages.

CONNECTION DIAGRAM

DIL-8,SOIC-8 (Top View)
J or N,D Packages

PARAMETER TEST CONDITION MIN TYP MAX UNITS

Oscillator Section

Frequency 175 202 228 kHz
Temperature Stability (Note 5) 2.5 %
Amplitude (Note 1) 1/3VDD V

Error Amplifier Section

Input Voltage COMP = 2.0V 1.95 2.00 2.05 V
Input Bias Current −1 1 µA
Open Loop Voltage Gain 60 80 dB
COMP Sink Current FB = 2.2V, COMP = 1.0V 0.3 2.5 mA
COMP Source Current FB = 1.3V, COMP = 4.0V −0.2 −0.5 mA

PWM Section

Maximum Duty Cycle 75 78 81 %
Minimum Duty Cycle COMP = 0V 0 %

Current Sense Section

Gain (Note 2) 1.1 1.65 1.8 V/V
Maximum Input Signal COMP = 5.0V (Note 3) 0.9 1.0 1.1 V
Input Bias Current −200 200 nA
CS Blank Time 50 100 150 ns
Overcurrent Threshold 1.4 1.5 1.6 V
COMP to CS Offset CS = 0V 0.55 1.1 1.65 V

Output Section

OUT Low Level I = 100mA 0.4 1 V
OUT High Level I = –100mA, VDD − OUT 0.4 1 V
Rise/Fall Time CL = 1nF (Note 5) 20 100 ns

ELECTRICAL CHARACTERISTICSUnless otherwise stated these specifications apply for TA = −55°C to +125°C for

UCC1807-1/-2/-3;−40°C to +85°C for UCC2807-1/-2/-3;and 0°C to +70°C for UCC3807-1/-2/-3;VDD = 10V (Note 6), RA = 12kΩ,
RB = 4.7kΩ, CT = 330pF, 1.0µF capacitor from VDD to GND, TA = TJ.

ORDERING INFORMATION

UCC 807 —

UVLO Threshold
Package
Temperature Range