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Details, datasheet, quote on part number:TPS60402
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Datasheet text preview:
TPS60400, TPS60401, TPS60402, TPS60403 UNREGULATED 60-mA CHARGE PUMP VOLTAGE INVERTER
SLVS324 JULY 2001
features
applications
D Inverts Input Supply Voltage D Up to 60-mA Output Current D Only Three Small 1-µF Ceramic Capacitors
Needed
D Input Voltage Range From 1.6 V to 5.5 V D PowerSave-Mode for Improved Efficiency D D D D
at Low Output Currents (TPS60400) Device Quiescent Current Typical 100 µA Integrated Active Schottky-Diode for Start-Up Into Load Small 5-Pin SOT23 Package Evaluation Module Available TPS60400EVM178
D D D D D D
LCD Bias GaAs Bias for RF Power Amps Sensor Supply in Portable Instruments Bipolar Amplifier Supply Medical Instruments Battery-Operated Equipment
DBV PACKAGE (TOP VIEW) OUT IN CFLY 1 2 3 4 GND 5 CFLY+
description
The TPS6040x is a family of devices that generate an unregulated negative output voltage from an input voltage ranging from 1.6 V to 5.5 V. The devices are typically supplied by a preregulated supply rail of 5 V or 3.3 V. Due to its wide input voltage range, two or three NiCd, NiMH, or alkaline battery cells, as well as one Li-Ion cell can also power them. Only three external 1-µF capacitors are required to build a complete dc/dc charge pump inverter. Assembled in a 5-pin SOT23 package, the complete converter can be built on a 50 mm2 board area. Additional board area and component count reduction is achieved by replacing the Schottky diode that is typically needed for start-up into load by integrated circuitry. The TPS6040x can deliver a maximum output current of 60 mA with a typical conversion efficiency of greater than 90% over a wide output current range. Three device options with 20-kHz, 50-kHz, and 250-kHz fixed frequency operation are available. One device comes with a variable switching frequency to reduce operating current in applications with a wide load range and enables the design with low-value capacitors.
typical application circuit
TPS60400
C(fly) 3 CFLY Input 1.6 V to 5.5 V 2 CI 1 µF IN
1 µF 5
V O Output Voltage V
OUTPUT VOLTAGE vs INPUT VOLTAGE
0 IO = 60 mA 1 IO = 30 mA IO = 1 mA 2
CFLY+ OUT 1 CO 1 µF Output 1.6 V to 5 V, Max 60 mA
TPS60400 GND 4
3
4 TA = 25°C 5 0 1 2 3 4 VI Input Voltage V 5
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
Copyright 2001, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters.
POST OFFICE BOX 655303
· DALLAS, TEXAS 75265
1
TPS60400, TPS60401, TPS60402, TPS60403 UNREGULATED 60-mA CHARGE PUMP VOLTAGE INVERTER
SLVS324 JULY 2001
AVAILABLE OPTIONS PART NUMBER TPS60400DBV TPS60401DBV TPS60402DBV MARKING DBV PACKAGE PFKI PFLI PFMI TYPICAL FLYING CAPACITOR [µF] 1 10 3.3 FEATURE Variable switching frequency 50 kHz250 kHz Fixed frequency 20 kHz Fixed frequency 50 kHz
TPS60403DBV PFNI 1 Fixed frequency 250 kHz The DBV package is available taped and reeled. Add R suffix to device type (e.g. TPS60400DBVR) to order quantities of 3000 devices per reel. Add T suffix to device type (e.g. TPS60400DBVT) to order quantities of 250 devices per reel.
TPS60400 functional block diagram
VI VI VCFLY+ Vbe VO OSC CHG OSC 50 kHz VO > 1 V VI VO VCO_CONT VI / VO MEAS DC_ Startup Q Phase Generator
R Start FF S
Q
DC_ Startup
VI
Q1 + C(fly) Q Q2 Q3
VO MEAS
Q4 B Q5
VO
GND
VO < VI Vbe
Terminal Functions
TERMINAL NAME CFLY+ CFLY GND IN OUT NO. 5 3 4 2 1 I O I/O Positive terminal of the flying capacitor C(fly) Negative terminal of the flying capacitor C(fly) Ground Supply input. Connect to an input supply in the 1.6-V to 5.5-V range. Bypass IN to GND with a capacitor that has the same value as the flying capacitor. Power output with VO = VI Bypass OUT to GND with the output filter capacitor CO. DESCRIPTION
2
POST OFFICE BOX 655303
· DALLAS, TEXAS 75265
TPS60400, TPS60401, TPS60402, TPS60403 UNREGULATED 60-mA CHARGE PUMP VOLTAGE INVERTER
SLVS324 JULY 2001
detailed description
operating principle The TPS60400, TPS60401 charge pumps invert the voltage applied to their input. For the highest performance, use low equivalent series resistance (ESR) capacitors (e.g., ceramic). During the first half-cycle, switches S2 and S4 open, switches S1 and S3 close, and capacitor (C(fly)) charges to the voltage at VI. During the second half-cycle, S1 and S3 open, S2 and S4 close. This connects the positive terminal of C(fly) to GND and the negative to VO. By connecting C(fly) in parallel, CO is charged negative. The actual voltage at the output is more positive than VI, since switches S1S4 have resistance and the load drains charge from CO.
VI S1 C(fly) 1 µF S2 S3 CO 1 µF GND S4 VO (VI)
GND
Figure 1. Operating Principle charge-pump output resistance The TPS6040x devices are not voltage regulators. The charge pumps output source resistance is approximately 15 at room temperature (with VI = 5 V), and VO approaches 5 V when lightly loaded. VO will droop toward GND as load current increases. VO = (VI RO × IO) R O [ osc 1 C )4 R
2
(fly) RO = output resistance of the converter efficiency considerations
SWITCH
) ESR
CFLY
) ESRCO
(1)
The power efficiency of a switched-capacitor voltage converter is affected by three factors: the internal losses in the converter IC, the resistive losses of the capacitors, and the conversion losses during charge transfer between the capacitors. The internal losses are associated with the IC's internal functions, such as driving the switches, oscillator, etc. These losses are affected by operating conditions such as input voltage, temperature, and frequency. The next two losses are associated with the voltage converter circuit's output resistance. Switch losses occur because of the on-resistance of the MOSFET switches in the IC. Charge-pump capacitor losses occur because of their ESR. The relationship between these losses and the output resistance is as follows: PCAPACITOR LOSSES + PCONVERSION LOSSES = IO2 × RO RSWITCH = resistance of a single MOSFET-switch inside the converter fOSC = oscillator frequency The first term is the effective resistance from an ideal switched-capacitor circuit. Conversion losses occur during the charge transfer between C(fly) and CO when there is a voltage difference between them. The power loss is: P CONV.LOSS +
1 2
C (fly)
VI2 * VO 2 ) 1 CO VRIPPLE2 * 2VOVRIPPLE 2
osc
(2)
POST OFFICE BOX 655303
· DALLAS, TEXAS 75265
3
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