UCC2808A-2Q1

Manufacturer Part NumberUCC2808A-2Q1
ManufacturerTexas Instruments
UCC2808A-2Q1 datasheet
 


Specifications of UCC2808A-2Q1

Control MethodCurrentDuty Cycle(max)(%)50
Frequency(max)(khz)1000Uvlo Thresholds On/off(v)4.3/4.1
Pin/package8SOICRegulated Outputs(#)2
Operating Temperature Range(c)-40 to 125  
1
Page 1
2
Page 2
3
Page 3
4
Page 4
5
Page 5
6
Page 6
7
Page 7
8
Page 8
9
Page 9
10
Page 10
11
12
Page 1/12

Download datasheet (267Kb)Embed
Next
D
Qualified for Automotive Applications
D
ESD Protection Exceeds 1500 V Per
MIL-STD-883, Method 3015; Exceeds 200 V
Using Machine Model (C = 200 pF, R = 0)
D
Dual Output Drive Stages in Push-Pull
Configuration
D
Current Sense Discharge Transistor to
Improve Dynamic Response
D
130-µA Typical Starting Current
D
1-mA Typical Run Current
D
Operation to 1 MHz
D
Internal Soft Start
D
On-Chip Error Amplifier With 2-MHz Gain
Bandwidth Product
D
On Chip VDD Clamping
D
Output Drive Stages Capable of 500-mA
Peak-Source Current, 1-A Peak-Sink
Current
description
The UCC2808A is a family of BiCMOS push-pull, high-speed, low-power, pulse-width modulators. The
UCC2808A contains all of the control and drive circuitry required for off-line or dc-to-dc fixed frequency
current-mode switching power supplies with minimal external parts count.
The UCC2808A dual output drive stages are arranged in a push-pull configuration. Both outputs switch at half
the oscillator frequency using a toggle flip-flop. The dead time between the two outputs is typically 60 ns to
200 ns depending on the values of the timing capacitor and resistors, thus limiting each output stage duty cycle
to less than 50%.
The UCC2808A family offers a variety of package options and choice of undervoltage lockout levels. The family
has UVLO thresholds and hysteresis options for off-line and battery powered systems. Thresholds are shown
in the ordering information table.
The UCC2808A is an enhanced version of the UCC2808 family. The significant difference is that the A versions
feature an internal discharge transistor from the CS pin to ground, which is activated each clock cycle during
the oscillator dead time. The feature discharges any filter capacitance on the CS pin during each cycle and helps
minimize filter capacitor values and current sense delay.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
UCC2808A 1Q1, UCC2808A 2Q1
LOW POWER CURRENT MODE PUSH PULL PWM
SGLS183A − AUGUST 2003 − REVISED APRIL 2008
COMP
OUTA
VDD
COMP
FB
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
D PACKAGE
(TOP VIEW)
1
8
VDD
OUTA
2
7
FB
OUTB
CS
3
6
GND
RC
4
5
PW PACKAGE
(TOP VIEW)
1
8
OUTB
2
7
GND
3
6
RC
4
5
CS
Copyright  2008 Texas Instruments Incorporated
1

UCC2808A-2Q1 Summary of contents

  • Page 1

    ... UVLO thresholds and hysteresis options for off-line and battery powered systems. Thresholds are shown in the ordering information table. The UCC2808A is an enhanced version of the UCC2808 family. The significant difference is that the A versions feature an internal discharge transistor from the CS pin to ground, which is activated each clock cycle during the oscillator dead time ...

  • Page 2

    ... UCC2808A 1Q1, UCC2808A 2Q1 LOW POWER CURRENT MODE PUSH PULL PWM SGLS183A − AUGUST 2003 − REVISED APRIL 2008 UVLO T A Option −40°C to 125°C −40°C to 125°C 12.5 V/8.3 V 12.5 V/8.3 V −40°C to 125°C −40°C to 125°C 4.3 V/4.1 V 4.3 V/4.1 V † For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI web site at http://www.ti.com. ‡ ...

  • Page 3

    ... Currents are positive into, negative out of the specified terminal. Consult Packaging Section of the Power Supply Control Data Book (TI Literature Number SLUD003) for thermal limitations and considerations of packages. electrical characteristics −40°C to 125°C for the UCC2808AQ-x, VDD = 10 V (see Note 6), 1-µF A capacitor from VDD to GND kΩ 330 pF T ...

  • Page 4

    ... UCC2808A 1Q1, UCC2808A 2Q1 LOW POWER CURRENT MODE PUSH PULL PWM SGLS183A − AUGUST 2003 − REVISED APRIL 2008 electrical characteristics −40°C to 125°C for the UCC2808AQ-x, VDD = 10 V (see Note 6), 1-µF A capacitor from VDD to GND kΩ 330 pF T PARAMETER ...

  • Page 5

    ... However, the error amplifier is internally current limited, so that zero duty cycle can be externally forced by pulling COMP to GND. The UCC2808A family features built-in full-cycle soft start. Soft start is implemented as a clamp on the maximum COMP voltage. CS: The input to the PWM, peak current, and overcurrent comparators. The overcurrent comparator is only intended for fault sensing ...

  • Page 6

    ... A 1-µF decoupling capacitor is recommended. A 200-kHz push-pull application circuit with a full-wave rectifier is shown in Figure 2. The output maximum and is electrically isolated from the input. Since the UCC2808A is a peak-current-mode controller the 2N2907 emitter following amplifier (buffers the CT waveform) provides slope compensation which is necessary for duty ratios greater than 50%. Capacitor decoupling is very important with a single ground IC controller, and a 1 µ ...

  • Page 7

    ... LOW POWER CURRENT MODE PUSH PULL PWM APPLICATION INFORMATION Figure 2. Typical Application Diagram: 48-V In, 5-V, 50-W Output • POST OFFICE BOX 655303 DALLAS, TEXAS 75265 UCC2808A 1Q1, UCC2808A 2Q1 SGLS183A − AUGUST 2003 − REVISED APRIL 2008 UDG-00096 7 ...

  • Page 8

    ... UCC2808A 1Q1, UCC2808A 2Q1 LOW POWER CURRENT MODE PUSH PULL PWM SGLS183A − AUGUST 2003 − REVISED APRIL 2008 OSCILLATOR FREQUENCY vs EXTERNAL RC VALUES 1000 C = 100 220 330 pF 100 C = 1000 820 560 100 150 200 RT − Timing Resistor − k Ω ...

  • Page 9

    ... SOIC UCC2808AQDR-1Q1 ACTIVE SOIC UCC2808AQDR-2G4Q1 ACTIVE SOIC UCC2808AQDR-2Q1 ACTIVE SOIC (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. ...

  • Page 10

    ...

  • Page 11

    ...

  • Page 12

    ... Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are sold subject to TI’ ...