HSMC H3842P, HSMC3842 Datasheet

HI-SINCERITY

MICROELECTRONICS CORP.

Spec. No. : HP200202
Issued Date : 1998.08.01
Revised Date : 2002.12.03
Page No. : 1/10

H3842P / HSMC3842

HIGH PERFORMANCE CURRENT MODE CONTROLERS

Description

The H3842P/HSMC3842 are high performance fixed frequency current mode
controllers. They are specifically designed for Off-Line and DC To DC converter
applications offering the designer a cost-effective solution with minimal external
components. These integrated circuits feature a trimmed oscillator for precise duty
cycle control. A temperature compensa-ted reference, high gain error amplifier,
current sensing comparator, and a high current totem pole output ideally suited for
driving a power MOSFET. Also included are protective features consisting of input and reference undervoltage
lockouts each with hysteresis, cycle-by-cycle current limiting, programmable output deadtime, and a latch for single
pulse metering.

Features

• Trimmed Oscillator for Precise Frequency Control

• Oscillator Frequency Guaranteed at 250 kHz

• Current Mode Operation to 500 kHz

• Automatic Feed Forward Compensation

• Latching PWM for Cycle-By-Cycle Current Limiting

• Internally Trimmed Reference with Undervoltage Lockout

• High Current Totem Pole Output

• Undervoltage Lockout with Hysteresis

• Low Startup and Operating Current

DIP-8Pin

Absolute Maximum Ratings

Symbol Parameter Value Unit

Vi Supply Voltage (low impedance source) 30 V
Vi Supply Voltage (Ii<30mA) Self Limiting
Io Output Current

±1

Eo Output Energy (capacitive load) 5 uJ

Analog Inputs (pin 2, 3) -0.3 to 5.5 V
Error Amplifier Output Sink Current 10 mA

Ptot

Power Dissipation at Tamb≤25

o

C

1.25 W

Tstg Storage Temperature Range -65 to 150

TJ Junction Operating Temperature -40 to 150
TL Lead Temperature (soldering 10s) 300

Block Diagram

Vcc

Ground

RT/CT

VFB

COMP

Current

Sense

7

5

4

2

1

3

34V

Error AMP.

+

-

2.50V

UVLO

OSC

S/R

2R

5V

REF

R

VREF Good

Logic

1V

Comparator

Current

Sense

Internal

Bias

T

S

R

PWM Latch

8

6

VREF
5V 50mA

Output

A

o

C

o

C

o

C

H3842P HSMC Product Specification

HI-SINCERITY

MICROELECTRONICS CORP.

Pin Connection (Top View)

DIP-8P Function Description

This pin is the Error Amplifier output and is made available for
loop compensation.
This is the inverting input of the Error Amplifier. It’s normally
connected to the switching power supply output through a
resistor divider.
A voltage proportional to inductor current is connected to this
input. The PWM uses this information to terminate the output
switch conduction.
The oscillator frequency and maximum output duty cycle are
programmed by connecting resistor RT to Vref and cpacitor CT
to ground. Operation to 500kHz is possible.

This output directly drives the gate of a power MOSFET. Peak
currents up to 1A are sourced and sunk by this pin.

This is the reference output. It provides charging current for
capacitor CT through resistor RT.

5678

1234

Pin1: Compensation

Pin2: Voltage Feedback

Pin3: Current Sense

Pin4: RT/CT

Pin5: Ground This pin is the combined control circuitry and power ground.

Pin6: Output

Pin7: Vcc This pin is the positive supply of the control IC.

Pin8: Vref

Spec. No. : HP200202
Issued Date : 1998.08.01
Revised Date : 2002.12.03
Page No. : 2/10

Thermal Data

Symbol Description Max. Units

Rth j-amb Thermal Resistance Junction-ambient 100

Electrical Specifications

Parameter Test Conditions Min. Typ. Max. Units

Under-Voltage Lockout Sect ion

Start Threshold 14.5 16 17.5 V
Min. Operating Voltage After Turn On 8.5 10 11.5 V

Electrical Characteristics

Unless otherwise stated, specifications apply for 0≤Ta≤70°C Vcc =15V (Note 1); RT=680Ω, CT=0.022uF for

triangular mode, RT=10k, CT=3.3nf for sawtooth mode

Parameter Test Conditions Min. Typ. Max. Units

Reference Section

Reference Output Voltage
Line Regulation
Load Regulation
Temperature. Stability
Total Output Variation Line , Load , Temp (Note 2) 4.82 - 5.18 V
Output Noise Voltage
Long Term Stability
Output Short current

Oscillator Section

Frequency

Frequency Chnge with Temperature

Frequency Change with Temperature

Oscillator Voltage Swing Peak to Peak - 1.7 - V

Discharge Current

Tj=25°C,Io=1mA
12V≤Vin≤25V
1mA≤Io≤20mA

(Note 2)

10Hz≤f≤10kHz,Tj=25°C
Ta=125°C,1000Hrs
Ta=25°C

Tj=25°C
Tlow≤Ta≤Thigh
12V≤Vcc≤25V
Tlow≤Ta≤Thigh (Note 2)
Tj=25°C

Tj=25°C
Tlow≤Ta≤Thigh

(Note 2)

(Note 2)

4.90 5 5.1 V

-2.020mV

-3.025mV

-0.2-

-50- uV

-5-mV

-30 -100 -180 mA

47 52 57 KHz
46 52 60 KHz

-0.21 %

-5-%

-0.5- %

7.8 8.3 9.3 mA

7.2 - 9.5 mA

mV/°C

o

C/W

H3842P HSMC Product Specification

HI-SINCERITY

MICROELECTRONICS CORP.

Spec. No. : HP200202
Issued Date : 1998.08.01
Revised Date : 2002.12.03
Page No. : 3/10

Parameter Test Conditions Min. Typ. Max. Units

Error Amplifier Section

Voltage Feedback Input Vo=2.5V 2.42 2.50 2.58 V
Input Bias Current VFB=5.0V - -0.1 -2.0 uA
Open Loop Voltage Gain
Unity Gain Bandwidth
Power Supply Rejection Ratio

Output Current

Output Voltage Swing
High State

2≤Vo≤4 V
Tj=25°C

(Note 2)

12V≤Vcc≤25V

Sink (Vo=1.1V, VFB=2.7V) 2.0 12 - mA
Source (Vo=5.0V, VFB=2.3V) -0.5 -1.0 - mA

VFB=2.3V, RL=15K to ground 5 6 - V

65 90 - dB

0.7 1.0 - MHz
60 70 - dB

Low State VFB=2.7V, RL=15K to Vref - 0.7 1.1 V

Current Sense Section

Current Sense Input Voltage Gain
Maximum Current Sense Input
Thresold
Ppwer Supply Rejection Ratio

(Notes 3 & 4)

(Note 3)

12V≤Vcc≤25V

(Note 3)

2.85 3.0 3.15 V/V

0.9 1.0 1.1 V

-70- dB
Input Bias Current - -2.0 -10 uA
Propagation Delay

Tj=25°C

(Note 2)

- 150 300 nS

Output Section

Low State (Isink=20mA) - 0.1 0.4 V

Output Voltage

Low State (Isink=200mA) - 1.5 2.2 V
High State (Isource=20mA) 13 13.5 - V

High State (Isource=200mA) 12 13.4 - V
Output Voltage Rise Time
Output Voltage Fall Time

Tj=25°C, CL=1.0nF

Tj=25°C, CL=1.0nF

(Note 2)

(Note 2)

- 50 150 nS

- 50 150 nS

Output Voltage with UVLO Activated Vcc=6V , Isink=1.0mA - -0.1 -1.1 V

Total Device

Start-Up Current - 0.1 0.5 mA
Operating Supply Current Vpin2=Vpin3=0, RT=10K, CT=3.3nF - 11 17 mA
Vcc Zener Voltage Icc=25 mA - 34 - V

Note 1: Adjust Vcc above the start threshold before setting at 15V.
Note 2: These parameters, although guaranteed are not 100% tested in production.
Note 3: Parameter measured at trip point of latch with Vpin2=0.

Note 4: Gain defined as: A=Vpin1/Vpin3, 0≤Vpin3≤0.8V

H3842P HSMC Product Specification