Cherry Semiconductor CS5661EDWR16, CS5661EDW16 Datasheet

1

Features

■ Oscillator has Precise

Duty Cycle
Limit and Frequency
Control

■ 500kHz Current Mode

Operation

■ Automatic Feed Forward

Compensation

■ Separate Latching PWMs

for Cycle-By-Cycle
Current Limiting

■ Internally Trimmed

Reference with
Undervoltage Lockout

■ Switchable Second

Output

■ Two High Current Totem

Pole Outputs

■ Input Undervoltage

Lockout with Hysteresis

■ 8.4V Start Up Voltage

Threshold

Package Options

16 Lead SO Wide

CS5661

High Performance Dual Channel

Current Mode Controller with ENABLE

1

SYNC

2
3
4
5
6
7
8

C

T

R

T

V

FB

1

COMP

1

SENSE

1

V

OUT

1

Gnd

16
15
14
13
12
11
10

9

V

CC

V

REF

ENABLE

2

V

FB

2

COMP2
SENSE

2

V

OUT

2

Pwr Gnd

CS5661

Description

The CS5661 is a high performance,
fixed frequency, dual current mode
controller specifically designed for
Off-Line and DC to DC converter
applications. It offers the designer a
cost effective solution with minimal
external components. This integrat­ed circuit features a unique oscilla­tor for precise duty cycle limit and
frequency control, a temperature
compensated reference, two high
gain error amplifiers, two current
sensing comparators, and two high

current totem pole outputs ideally
suited for driving power MOSFETs.
V

OUT

2

output is switchable via the

ENABLE2pin.

Also included are protective fea­tures consisting of input and refer­ence undervoltage lockouts, each
with hysteresis, cycle-by-cycle cur­rent limiting, and a latch for single
pulse metering of each output.

The CS5661 is pin compatible with
the MC34065L.

Block Diagram

Rev. 2/2/99

Cherry Semiconductor Corporation

2000 South County Trail, East Greenwich, RI 02818

Tel: [phone] Fax: [phone]

Email: [e-mail]

Web Site: www.cherry-semi.com

A Company

®

V

REF

Undervoltage

SYNC

C

T

R

T

Oscillator

V

Undervoltage

Lockout

Latching

PWM 1

CC

V

REF

Lockout

5.0V Ref

V

CC

V

OUT

1

COMP

ENABLE

COMP

Sense

1

V

OUT

2

Sense

2

+

-

Error
Amp 1

+

-

Amp 2

Error

Latching

PWM 2

Gnd

Pwr Gnd

V

FB

1

1

2

V

FB

2

2

2

Electrical Characteristics: (V

CC

= 15V, RT= 8.2kΩ, CT= 3.3nF, for typical values TA= 25˚C, for min/max values -40˚C < TA < 85˚C,

unless otherwise stated.

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

Absolute Maximum Ratings

Output Current, Source or Sink (Note 1)......................................................................................................................400mA

Output Energy (capacitive load per cycle) .......................................................................................................................5.0µJ

Current Sense, Enable and Voltage......................................................................................................................-0.3 to +5.5V

Feedback Inputs

Sync Input – High State (Voltage) ......................................................................................................................................5.5V

– Low State (Reverse Current) ...................................................................................................................-5.0mA

Error Amp Output Sink Current......................................................................................................................................10mA

Storage Temperature Range ................................................................................................................................-65 to +150°C

Operating Junction Temperature...................................................................................................................................+150°C

Lead Temperature Soldering

Reflow (SMD styles only) ......................................................................................60 sec. max above 183°C, 230°C peak

ESD Capability (Human Body Model) ...................................................................................................................................2kV

CS5661

■ Reference Section

Reference Output Voltage, I

OUT

= 1.0mA, TJ= 25°C 4.9 5.0 5.1 V

V

REF

Line Regulation 11V ≤ VCC≤ 15V 2.0 20.0 mV
Load Regulation 1.0mA ≤ I

OUT

≤ 10mA 3.0 30.0 mV

Total Output Variation over 4.85 5.15 V
Line, Load and Temperature

Output Short Circuit Current 30 100 mA

■ Oscillator and PWM Sections

Total Frequency Variation 11V ≤ VCC≤ 15V, T

low

≤ TA≤ T

high

46.0 49.5 53.0 kHz

over Line and Temperature
Frequency Change with 11V ≤ VCC≤ 15V 0.2 1.0 %

Voltage
Duty Cycle at each Output Maximum 46.0 49.5 52.0 %
SYNC Current High State VIN= 2.4V 170 250 µA

Low State VIN= 0.8V 80 160

■ Error Amplifiers

Voltage Feedback Input V

OUT

= 2.5V 2.42 2.50 2.58 V
Input Bias Current VFB= 5.0V -0.1 -1.0 µA
Open-Loop Voltage Gain 2.0V ≤ V

OUT

≤ 4.0V 65 100 dB

Unity Gain Bandwidth T

J

= 25°C (Note 5) 0.7 1.0 MHz

Power Supply Rejection Ratio V

CC

= 11V to 15V 60 90 dB

Output Current Source V

OUT

= 3.0V, VFB= 2.3V -0.45 -1.00 mA

Sink V

OUT

= 1.2V, VFB= 2.7V 2.00 12.00 mA

Output Voltage Swing High State R

L

= 15kΩ to ground,

VFB= 2.3V 5.0 6.2 V

Low State RL= 15kΩ to V

REF

,

VFB= 2.7V 0.8 1.1 V

3

CS5661

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

Note 1: Maximum package power dissipation limits must be observed.

Note 2: Low duty cycle pulse techniques are used during test to maintain
junction temperature as close to ambient as possible:

T

low

= -40°C ; T

high

=+85°C

Note 3: This parameter is measured at latch trip point with VFB=0V.

Note 4: Comparator gain is defined as:

AV=

Note 5: These parameters are guaranteed by design but not 100% tested
in production.

∆V Compensation

∆V Current Sense

■ Current Sense Section

Current Sense Input (Notes 3 and 4) 2.75 3.00 3.25 V/V
Voltage Gain

Maximum Current Sense (Note 3) 0.9 1.0 1.1 V
Input Threshold

Input Bias Current -2.0 -30.0 µA
Propagation Delay Current Sense Input to Output (Note 5) 150 300 ns

■ Output 2 Enable Pin

Enable Pin Voltage V
High State OUTPUT2enabled 3.5 V

REF

V

Low State OUTPUT2disabled 0.0 1.5 V
Low State Input Current VIL= 0V 100 250 400 µA

■ Drive Outputs

Output Voltage
Low State I

SINK

= 20mA 0.1 0.4 V

I

SINK

= 200mA 1.6 2.5 V

High State I

SOURCE

= 20mA 13.0 13.5 V

I

SOURCE

= 200mA 12.0 13.4 V

Output Voltage with (VCC= 6.0V, I

SINK

= 1.0mA) 0.1 1.1 V

UVLO Activated
Output Voltage Rise Time (CL= 1.0nF) Note 5 28 150 ns
Output Voltage Fall Time (CL= 1.0nF) Note 5 25 150 ns

■ Undervoltage Lockout Section

Start-Up Threshold 7.4 8.4 9.4 V
Minimum Operating Voltage
After Turn-On 6.8 7.8 8.8 V
Hysteresis 0.6 V

■ Total Device

Start-Up Current V

CC

= 6V 0.6 1.0 mA

Operating Current 20 25 mA

Electrical Characteristics: (V

CC

= 15V, RT= 8.2kΩ, CT= 3.3nF, for typical values TA= 25˚C, for min/max values -40˚C < TA < 85˚C,

unless otherwise stated.