Texas Instruments UC3860QTR, UC3860Q, UC3860N, UC3860DWTR, UC3860DW Datasheet

UC1860
UC2860
UC3860

Resonant Mode Power Supply Controller

FEATURES

• 3MHz VFO Linear over 100:1 Range

• 5MHz Error Amplifier with Controlled

Output Swing

• Programmable One Shot Timer—
Down to 100ns

• Precision 5V Reference

• Dual 2A Peak Totem Pole Outputs

• Programmable Output Sequence

• Programmab le Under Volta ge Locko ut

• Very Low Start Up Current

• Programmable Fault Management &

Restart Delay

• Uncommitted Comparator

DESCRIPTIO N

The UC1860 family of control ICs is a versatile system for resonant mode
power supply control. This device easily implements frequency modulate d
fixed-on-time control schemes as well as a number of other power supply
control schemes with its various dedicated and programmable features.

The UC1860 includes a precision voltage reference, a wide-bandwidth er­ror amplifier, a variable frequency oscillator operable to beyond 3MHz, an
oscillator-triggere d one-shot, dual high-current totem-pole output drivers,
and a programmable toggle flip-flop. The output mode is easily pro­grammed for various sequences such as A, off, B, off; A & B, off; or A, B,
off. The error amplifier contai ns precision output clamps that allow pro­gramming of minimum and maximum frequency.

The device also co ntain s an u ncommitted compa rator, a fast comparator
for fault sensing, progra mmable soft start circuitry, and a programmable
restart delay. Hic-up style response to faults is easily achieved. In addi­tion, the UC18 60 contains prog rammable under voltage lockout circuitry
that forces the output stages low and minimizes supply current during
start-up conditions.

BLOCK DIAGRAM

ABSOLUTE MAXI MUM RATING S

Supply Voltage ( pin 19) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20V

Output Current , Sourc e or Sink (pins 17 & 20)

DC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.8A

Pulse (0.5µs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.0A

Power Ground Voltag e. . . . . . . . . . . . . . . . . . . . . . . . . . . . ±0.2V

Inputs (pins 1, 2, 3, 4, 8, 9, 11, 12,

13, 14, 21, 22, 23 & 24). . . . . . . . . . . . . . . . . . . . . . -0. 4 t o 6V

Error Amp Output Curr ent , Source or Sink (pin 5). . . . . . . . 2mA

I

VFO Current (pin 7). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2mA

Compara to r Output Cur ren t (pin 15) . . . . . . . . . . . . . . . . . . 5mA

Compara to r Output Volt age (pin 15) . . . . . . . . . . . . . . . . . . 15V

Soft Start or Restart Delay Sink Curre nt (pins 22 & 23) . . . 5mA
Power Dissipation at T

A = 50°C (DIP) . . . . . . . . . . . . . . . 1.25W

Power Dissipation at T

A = 50°C (PLCC) . . . . . . . . . . . . . . . . 1W

Lead Temp era ture (Solder in g, 10 seconds) . . . . . . . . . . . 300°C

Note: All voltages are with respect to signal gro und an d a ll

currents are posit ive int o the spec ified t ermina l.
Pin numbers refer to the DI P.
Refer to Packag ing Sect ion of Databoo k fo r therma l
limitations and cons id era tion s of packa ges.

10/93

UC1860
UC2860
UC3860

ELECTRICAL CHARACTERISTICS:

PARAMETER CONDITIONS MIN TYP MAX UNITS

Reference Sec tio n

Output Volt age T

A = 25°C, IO = 0 4.95 5.00 5.05 V

I

O = 0, Over Temp 4.93 5.07 V

Line Regulatio n 10 ≤ V

CC ≤ 20V 2 15 mV

Load Regulation 0≤ I

O ≤ 10mA 2 25 mV

Output Noise Voltage* 10Hz ≤ f ≤ 10kHz 50 µV

RMS

Short Circuit Current VREF = 0V -150 -1 5 mA

Error Amplifier Section

Input Offs et Vo lta g e 2.8 ≤ V

CM ≤ 4.5V 1 8 mV

Input Bias Cur ren t 50 500 nA
Open Loop Gain dV

O = 1.5V 60 80 dB

PSRR 10 ≤ V

CC ≤ 20V 70 100 dB

Output Low ( V

O-VIVFO) -0.1 ≤ IO ≤ 0.1mA -8 0 8 mV

Output High (V

O-VIVFO ) -0.5 ≤ IO ≤ 0.5mA 1.9 2 2.1 V

Unity Gain Bandwidth* R

IN = 2k 4 5 MHz

Oscillato r Sect io n

Nominal Frequency* 1.0 1.5 2.0 MHz
dF/dI

OSC* 100 ≤ IVFO ≤ 500µA 2 3 4 GHz/A

*Guarant e e d by des ign but not 100% test ed.

Unless otherwise stat ed, all specif icat ions app ly for -55 °C ≤ TA ≤ 125°C for the
UC1860, -25°C ≤ T

A ≤ 85°C for the UC2860, 0 ≤ TA ≤ 70°C for the UC3860, VCC =

12V, C

VFO = 330pF, IVFO = 0.5mA, C = 330pF, and R = 2.7k, T A = TJ.

DIL - 24 (TOP VIEW)
J or N Package

PLCC-28, LCC-28
(TOP VIEW)
Q or L Package

PIN PACKAGE FUNCTION

FUNCTION PIN
S GND 1
I

VFO 2

C

VFO 3

RC 4
V

REF 5

CMP IN (-) 6
CMP IN (+) 7
TRIG 8
OSC DSBL 9
CMP OUT 10
N/C 11, 12
OUT A 13
PGND 14
N/C 15
V

CC 16

OUT B 17
N/C 18, 19
MODE 20
SFT STRT 21
RST DLY 22
UVLO 23
FLT (-) 24
FLT (+) 25
EA IN (+) 26
EA IN (-) 27
EA OUT 28

CONNECTION DIAGRAM

2

UC1860
UC2860
UC3860

ELECTRICAL CHARACTERISTICS:

PARAMETER CONDITIONS MIN TYP MAX UNITS

Oscillato r Sect io n (c ont’d)

Trig in Threshold 1.0 1.4 1.8 V
Trig in Open Circuit Volta ge 0.7 0.9 1.1 V
Trig in Delta (V

TH-VOC) 0.3 0.5 0.7 V

Trig in Input Resistance dV T

RIG = VOC to VTH 51225kΩ

Minimum Trig in Pulse Width* 3 10 ns
Osc. Disable Threshold 1.0 1.4 1.8 V

One Shot Ti m er

On Time* 150 200 250 ns
Clamp Frequency* I

VFO = 1.5m A 2.8 3.7 4.6 MHz

Dead Time* I

VFO =1.5mA 35 70 100 ns

Output Stage

Output Low Saturation 20mA 0.2 0.4 V

200mA 0.5 2.2 V

Output High Saturation -20mA 1.5 2.0 V

-200mA 1.7 2.5 V

Rise/Fall Time* C

LOAD = 1nF 1530ns

UVLO Low Satur at i on 20mA 0.8 1.5 V
Output M ode Low Input 0.4 V
Output Mode High Inpu t 2.0 V

Under Voltage Lockout Sectio n

V

CC Comparator Threshold On 16 17.3 18.5 V

Off 9.5 10.5 12 V

UVLO Comparat or Threshold On 3.6 4.2 4.8 V

Hysteresis 0.2 0.4 0.6 V

UVLO Input Resist ance UVLO = 4/V

CC = 8 102350kΩ

V

REF Comparator Threshold VCC = UVLO = VREF 4.5 4.9 V

Supply Current

I

CC VCC = 12V, VOSC DSBL = 3V 30 40 mA

I

START UVLO pin open

V

CC

= VCC (on) -0.3V

0.3 0.5 mA

Fault Compar ator

Input Offs et Vo lta g e −0.3 ≤ V

CM ≤ 3V 2 10 mV

Input Bias Cur ren t V

CM = 0V 100 200 µA

Input Offs et Cu rr ent V

CM = 0V 10 3 0 µA

Propagation De lay To Out put * ±50mV input 100 150 ns

Uncommitted Comparator

Input Offs et Vo lta g e -0.3 ≤ V

CM ≤ 3V 2 10 mV

Input Bias Cur ren t V

CM = 0V 100 200 µA

Input Offs et Cu rr ent V

CM = 0V 10 3 0 µA

Output Low Volt age I

O = 2mA 0.3 0.5 V

Propagation De lay To Sat * ±50mV input, 2.5k load to 5V 50 100 ns

Soft Start/Resta rt Co ntrol Sect ion

Saturation Volta ge (2 pins) I

SINK = 100µA0.20.5V

Charge Current (2 pins) 2 5 10 µA
Restart Delay Threshold 2.8 3.0 3.2 V

*Guarant e e d by des ign but not 100% test ed.

Unless otherw ise stated, all speci fications app ly for -55°C ≤ TA ≤ 125°C for the
UC1860, -25° ≤ TA ≤ 85°C for the UC2860, 0 ≤ TA ≤ 70°C for the UC 3860 , V CC =
12V, CVFO = 330pF, IVFO = 0.5mA, C = 330pF, and R = 2.7k, TA = TJ.

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