LTC1551L - Low Noise, Switched Capacitor Regulated Voltage Inverters

The LTC1550L/LTC1551L are switched capacitor charge pump voltage inverters which include internal linear post-regulators to minimize output ripple. The LTC1550L fixed output voltage versions include ±4.1V, ±2.5V and ±2V with ripple voltages typically below 1mVP-P. The LTC1550L is also available in an adjustable output voltage version. The LTC1550L/LTC1551L are ideal for use as bias voltage generators for GaAs transmitter FETs in portable RF and cellular telephone applications.

The LTC1550L/LTC1551L operate from single 2.7V to 5.5V supplies and draw typical quiescent currents of 3.5mA with a 5V supply. Each device includes a TTL compatible Shutdown pin which drops supply current to 0.2µA typically. The LTC1550L Shutdown pin is active low (SHDN), while the LTC1551L Shutdown pin is active high (SHDN). Only four external components are required: an input bypass capacitor, two 0.1µF charge pump capacitors and a filter capacitor at the linear regulator output. The adjustable LTC1550L/LTC1551L require two additional resistors to set the output voltage. The LTC1550L/LTC1551L will supply up to 20mA (depending on VCC to VOUT range), while maintaining guaranteed output regulation of ±2.5%.

Both fixed voltage and adjustable LTC1550L/LTC1551L are available in 8-lead MSOP and SO plastic packages: the adjustable LTC1550L is also available in a 16-pin SSOP with the REG pin.

Features

Regulated Negative Voltage from a Single Positive Supply
Low Output Ripple: Less Than 1mVP-P Typ
High Charge Pump Frequency: 900kHz Typ
Small Charge Pump Capacitors: 0.1µF
Requires Only Four External Capacitors
Fixed ±4.1V, ±2.5V, ±2V or Adjustable Output
Shutdown Mode Drops Supply Current to <1µA
High Output Current: Up to 20mA (Depending on VCC to VOUT Range)
Output Regulation: 2.5% Over Line, Load and Temperature
Available in 8-Lead MSOP, 8-Lead Narrow SO and 16-Lead Narrow SSOP

Typical Application

Applications

GaAs FET Bias Generators
Negative Supply Generators
Battery-Powered Systems
Single Supply Applications

Packaging

Order Information

Part Number	Package	Temp	Price(1-99)	Price (1k)*
LTC1551LCMS8-4.1#PBF	MS-8	C	$2.25	$1.90
LTC1551LCMS8-4.1#TRPBF	MS-8	C		$1.96
LTC1551LCMS8#PBF	MS-8	C	$2.25	$1.90
LTC1551LCMS8#TRPBF	MS-8	C		$1.96
LTC1551LCS8-4.1#PBF	SO-8	C	$2.00	$1.70
LTC1551LCS8-4.1#TRPBF	SO-8	C		$1.76
LTC1551LCS8#PBF	SO-8	C	$2.00	$1.70
LTC1551LCS8#TRPBF	SO-8	C		$1.76