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Delphi Row Column Power Supply

The Delphi Row Column Power Supply (RPS), from a 5-volt input, creates 5 voltage supplies for LCD Row and Column ICs. The main output is VLCD which is capable of sourcing 7.5mA of output current at voltages up to 20 volts. This high VLCD voltage is created from an on-chip boost circuit and an external 680uH inductor. The voltage of the VLCD output can be controlled by the duty cycle of the signal placed on the OSCEN pin. The other 4 outputs of the RPS, V1, V2, V3, and V4, are intermediate voltage supplies required by the Row and Column ICs to generate LCD drive waveforms. The output voltages of these supplies are set from an internal precision resistor divider. These output levels are set to 8/9, 7/9, 2/9, and 1/9 of VLCD for a 1/9 bias configuration. The RPS allows for 3 different bias configurations to optimize the output voltages to the size of the display that is being driven. The three bias configurations are 1/9, 1/7, and 1/5. The V1 and V4 outputs are capable +/-2mA of current, and the V2 and V3 outputs are capable of +/-6mA of current.

Features

Up to 20V VLCD output from 5V input
Four regulated supplies for LCD power requirements
1/9, 1/7, 1/5 bias settings for different multiplex rates

Packaging

16-Pin SOIC

Typical Applications

Passive LCD Displays
Automotive Electronics

Recommended Operating Conditions
Characteristic	Symbol	Value	Unit
Supply Voltage	VDD	4.75 to 5.25	V
Power Down	PD	-0.5 to VDD 0.5	V
Oscillator Enable	OSCEN	-0.5 to VDD 0.5	V
Operating Temperature Range, Ambient	Ta	-40 to 105	°C

Absolute Maximum Ratings
Characteristic	Symbol	Value	Unit
Supply Voltage	VDD	-0.6 to 6.0	V
Power Down	PD	-0.6 to VDD 6	V
Oscillator Enable	OSCEN	-0.6 to VDD 6	V
Storage Temperature	Tstg	-40 to 150	°C
Maximum Junction Temperature		150	°C

Electrical Performance Characteristics
Characteristics	Symbol	Condition	Min	Max	Typ	Unit
OSCEN, PD Inputs
Input Low Voltage	Vil			0.3 * VDD		V
Input High Voltage	Vih		0.7 * VDD			V
Input Current	lin	Vin = 0 volts	-10	10		µA
Input Current	lin	Vin = VDD	-10	10		µA
VLCD Output
VLCD Output	VLCD	100% Duty on OSCEN		30.0		V
VLCD Output	VLCD	90% Duty on OSCEN	20.0			V
VLCD Output	VLCD	50% Duty on OSCEN			15.0	V
VLCD Output	VLCD	0% Duty on OSCEN		VDD		V
V1, V2, V3, V4 Outputs		BIAS1, BIAS2, BAS3 open; VLCD=3D 5 to 21 volts
V1 Output	V1	lout = ± 2 mA	(8/9*VLCD) -2%	(8/9*VLCD) 2%		V
V2 Output	V2	lout = ± 6 mA	(7/9*VLCD) -2%	(7/9*VLCD) 2%		V
V3 Output	V3	lout = ± 6 mA	(2/9*VLCD) -2%	(2/9*VLCD) 2%		V
V4 Output	V4	lout = ± 2 mA	(1/9*VLCD) -2%	(1/9*VLCD) 2%		V
BIAS1, BIAS2, BIAS3 Inputs		VLCD = 5 to 21 volts
BIAS1 Voltage	Vbias1	lout = 0mA	(7/9*VLCD) -2%	(7/9*VLCD) 2%		V
BIAS2 Voltage	Vbias2	lout = 0mA	(5/9*VLCD) -2%	(5/9*VLCD) 2%		V
BIAS3 Voltage	Vbias3	lout = 0mA	(3/9*VLCD) -2%	(3/9*VLCD) 2%		V
OSC Frequency	OSCfreq		125	300	275	kHz
Turn-on time	Ton	Time from PD < Vil until VLCD within 2% of final value		100		mS
Turn-off time	Toff	Time from PD > Vih until VLCD < 5 volts		100		mS

Delphi Row Column Power Supply (57k)