Microsemi Corporation SG1846F-DESC, SG1846J, SG1846J-883B, SG1846J-DESC, SG1846L Datasheet

SG1846/SG2846/SG3846

CURRENT MODE PWM CONTROLLER

DESCRIPTION

The SG1846 family of control ICs provides all of the necessary features to implement fixed frequency, current mode control schemes while maintaining a minimum external parts count. The superior performance of this technique can be measured in improved line regulation, enhanced load response characteristics, and a simpler, easier-to-design control loop. Topological advantages include inherent pulse-by-pulse current limiting capability, automatic symmetry correction for push-pull converters, and the ability to parallel “power modules” while maintaining equal current sharing.

Protection circuitry includes built-in under-voltage lockout and programmable current limit in addition to soft start capability. A shutdown function is also available which can initiate either a complete shutdown with automatic restart or latch the supply off.

Other features include fully latched operation, double pulse suppression, deadtime adjust capability, and a ±1% trimmed bandgap reference.

FEATURES

∙Automatic feed forward compensation

∙Programmable pulse by pulse current limiting

∙Automatic symmetry correction in push-pull configuration

∙Enhanced load response characteristics

∙Parallel operation capability for modular power systems

∙Differential current sense amplifier with wide common mode range

∙Double pulse suppression

∙200mA totem-pole outputs

∙± 1% bandgap reference

∙Under-voltage lockout

∙Soft-start capability

∙Shutdown capability

∙500KHz operation

HIGH RELIABILITY FEATURES - SG1846

♦Available to MIL-STD - 883

♦Radiation data available

♦LMI level "S" processing available

BLOCK DIAGRAM

4/90 Rev 1.1 2/94	LINFINITY Microelectronics Inc.
Copyright ã 1994	11861 Western Avenue ∞ Garden Grove, CA 92841
1	[phone] ∞ FAX: [phone]

SG1846

ABSOLUTE MAXIMUM RATINGS (Note 1 and 2)

Supply Voltage (+VIN) ..........................................................

40V

Sync Output Current ...........................................................

5mA

Collector Supply Voltage(VC) ..............................................

40V

Error Amplifier Output Current

............................................

5mA

Analog Inputs (Pins 3, 4, 5, 6, & 16) ......................

-0.3V to +VIN

Oscillator Charging current (Pin .....................................9)

5mA

Logic Input ...........................................................

-0.3V to 5.5V

Operating Junction Temperature

Soure/Sink Load current (continuous)

..........................

200mA

Hermetic (J, L, F Packages) ........................................

150°C

Source/Sink Load Current (peak, 200ns) ......................

500mA

Plastic (N, DW Package) .............................................

150°C

Reference Load Current ..................................................

30mA

Storage Temperature Range ............................

-65°C to 150°C

Soft Start Sink Current .....................................................

50mA

Lead Temperature (Soldering, ..................10 Seconds)

300°C

Note 1. Values beyond which damage may occur.

Note 2. Pin numbers refer to ceramic J package.

THERMAL DATA

J Package:

Note A. Junction Temperature Calculation: TJ = TA + (PD x θJA).

Thermal Resistance-Junction to Case, θJC ..................

30°C/W

Thermal Resistance-Junction to Ambient, θJA ..............

80°C/W

Note B. The above numbers for θJC are maximums for the limiting

N Package:

thermal resistance of the package in a standard mount-

θ JA

Thermal Resistance-Junction to Case, θJC ..................

40°C/W

ing configuration. The

numbers are meant to be

Thermal Resistance-Junction to Ambient, θJA

65°C/W

guidelines for the thermal performance of the device/pc-

board system. All of the above assume no ambient

DW Package:

Thermal Resistance-Junction to Case, θJC ...................

40°C/W

airflow.

Thermal Resistance-Junction to Ambient, θJA .............

95°C/W

F Package:

Thermal Resistance-Junction to Case, θJC ..................

70°C/W

Thermal Resistance-Junction to Ambient, θJA ...........

115°C/W

L Package:

Thermal Resistance-Junction to Case, θJC ..................

35°C/W

Thermal Resistance-Junction to Ambient, θJA ...........

120°C/W

RECOMMENDED OPERATING CONDITIONS (Note 3)

2KΩ to 100KΩ

Supply Voltage Range ...............................................

8V to 40V

Oscillator Timing Resistor (RT) ...........................

Collector Supply Voltage Range .............................

4.5V to 40V

Oscillator Timing Capacitor (CT ....................)

1000 pF to 0.1µF

Source/Sink Output Current (continuous) ......................

100mA

Operating Ambient Temperature Range

Source/Sink Output Current (peak 200ns) ....................

200mA

SG1846 ...........................................................

-55°C to 125°C

Reference Load Current ...........................................

0 to 10mA

SG2846 .............................................................

-25°C to 85°C

Oscillator Frequency Range ...........................

1KHz to 500KHz

SG3846 ................................................................

0°C to 70°C

Note 3. Range over which the device is functional.

ELECTRICAL CHARACTERISTICS

(Unless otherwise specified, these specifications apply over the operating ambient temperatures for SG1846/SG1847 with -55°C ≤ TA ≤ 125°C, SG2846

with -25°C ≤ TA ≤ 85°C, SG3846 with 0°C ≤ TA ≤ 70°C, +VIN = 15V. Low duty cycle pulse testing techniques are used which maintains junction and

case temperatures equal to the ambient temperature.)

Parameter

Test Conditions

SG1846

SG3846

Units

SG2846

Min.

Typ.

Max.

Min.

Typ.

Max.

Reference Section

Output Voltage

TJ = 25°C, I O = 1mA

5.05

5.10

5.15

5.00

5.10

5.20

V

Line Regulation

VIN = 8V to 40V

5

20

5

20

mV

Load Regulation

IL = 1mA to 10mA

3

15

3

15

mV

Temperature Stability (Note 4)

0.4

0.4

mV/°C

Total Output Variation (Note 4)

Line, Load and Temperature

5.00

5.20

4.95

5.25

V

Output Noise Voltage (Note 4)

10Hz ≤ f ≤ 10KHz. TJ = 25°C

100

100

µV

Long Term Stability (Note 4)

TJ = 125°C, 1000Hrs.

5

5

mV

Short Circuit Output Current

VREF = 0V

-10

-45

-10

-45

mA

4/90 Rev 1.1 2/94

LINFINITY Microelectronics Inc.

Copyright ã 1994	11861 Western Avenue ∞ Garden Grove, CA 92841
2	[phone] ∞ FAX: [phone]

											SG1846
ELECTRICAL CHARACTERISTICS (continued)
	Parameter		Test Conditions	SG1846				SG3846				Units
				SG2846
				Min.		Typ.	Max.	Min.	Typ.		Max.
	Oscillator Section (Note 9)
	Initial Accuracy	TJ = 25°C		39	43		47	39	43	47		KHz
	Voltage Stability	VIN = 8V to 40V			1		2		1	2		%
	Temperature Stability (Note 4)	Over Operating Range			1				1			%
	Sync Output High Level			3.9	4.35			3.9	4.35			V
	Sync Output Low Level				2.3		2.5		2.3	2.5		V
	Sync Input High Level	Pin 8 = 0V		3.9				3.9				V
	Sync Input Low Level	Pin 8 = 0V					2.5			2.5		V
	Sync Input Current	Sync Voltage = 5.25V, Pin 8 = 0V			1.2		1.5		1.2	1.5		mA
	Error Amp Section
	Input Offset Voltage				0.5		5		0.5	10		mV
	Input Bias Current				-0.6		-1		-0.6	-2		µA
	Input Offset Current				40		250		40	250		nA
	Common Mode Range	VIN = 8V to 40V		0			VIN-2V	0			VIN-2V	V
	Open Loop Voltage Gain	VO = 1.2V to 3V, VCM = 2V		80	105			80	105			dB
	Unity Gain Bandwidth (Note 4)	TJ = 25°C		0.7	1.0			0.7	1.0			MHz
	CMRR	VCM = 0V to 38V, VIN = 40V		75	100			75	100			dB
	PSRR	VIN = 8V to 40V		80	105			80	105			dB
	Output Sink Current	VID = - 15mV to -5V, VPIN 7 = 1.2V		2	6			2	6			mA
	Output Source Current	VID = 15mV to 5V, VPIN 7 = 2.5V		-0.4	-0.5			-0.4	-0.5			mA
	High Level Output Voltage	RL = 15KΩ (Pin 7)		4.3	4.6			4.3	4.6			V
	Low Level Output Voltage	RL = 15KΩ (Pin 7)			0.7		1		0.7	1		V
	Current Sense Amplifier Section
	Amplifier Gain (Notes 5 & 6)	VPIN 3 = 0V, Pin 1 Open		2.5	2.75		3.0	2.5	2.75	3.0		V
	Maximum Differential (Note 6)	Pin 1 Open	RL = 15KΩ (Pin 7)
	Input Signal (VPIN 4 - VPIN 3)(Note 5)			1.1	1.2			1.1	1.2			V
	Input Offset Voltage (Note 5)	VPIN 1 = 0.5V, Pin 7 Open			5		25		5	25		mV
	CMRR	VCM = 1V to 12V		60	83			60	83			dB
	PSRR	VIN = 8V to 40V		60	84			60	84			dB
	Input Bias Current (Note 5)	VPIN 1 = 0.5V,	Pin 7 Open		-2.5		-10		-2.5	-10		µA
	Input Offset Current (Note 5)	VPIN 1 = 0.5V,	Pin 7 Open		0.08		1		0.08	1		µA
	Input Common Mode Range			0			VIN -3	0			VIN -3	V
	Delay to Outputs (Note 4)	TJ = 25°C			200		500		200	500		ns
	Current Limit Adjust Section
	Current Limit Offset Voltage(Note 5)	VPIN 3 = 0, VPIN 4 = 0V, Pin 7 Open		0.45	0.5		0.55	0.45	0.5	0.55		V
	Input Bias Current	VPIN 5 = VREF,	VPIN 6 = 0V		-10		-30		-10	-30		µA
	Shutdown Terminal Section
	Threshold Voltage			250	350		400	250	350	400		mV
	Input Voltage Range			0			VIN	0			VIN	V
	Minimum Latching Current
	(IPIN 1) (Note 7)			3.0	1.5			3.0	1.5			mA
	Maximum Non-Latching Current
	(IPIN 1) (Note 8)				1.5		0.8		1.5	0.8		mA
	Delay to Outputs (Note 4)	TJ = 25°C			300		600		300	600		ns
	Output Section
	Collector Emitter Voltage			40				40				V
	Collector Leakage Current	VC = 40V					200			200		µA
	Output Low Level	ISINK = 20mA			0.1		0.4		0.1	0.4		V
		ISINK = 100mA			0.4		2.1		0.4	2.1		V
	Output High Level	ISOURCE = 20mA		13	13.5			13	13.5			V
		ISOURCE = 100mA		12	13.5			12	13.5			V
	Rise Time (Note 4)	CL = 1nF, TJ = 25°C			50		300		50	300		ns
	Fall Time (Note 4)	CL = 1nF, TJ = 25°C			50		300		50	300		ns

4/90 Rev 1.1 2/94

LINFINITY Microelectronics Inc.

Copyright ã 1994	11861 Western Avenue ∞ Garden Grove, CA 92841
3	[phone] ∞ FAX: [phone]