TEA1202TS_00 Просмотр технического описания (PDF) - Philips Electronics

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производитель

TEA1202TS_00

Battery power unit

Philips Electronics 

Philips Semiconductors

Battery power unit

Objective specification

TEA1202TS

PINNING

SYMBOL

LX1

SHDWN0

SHDWN2

UPOUT/DNIN

ILIM

OUT1

FB1

GND

FB2

OUT2

IN2

LBI2

LBI1

LBO

Vref

FB0

GND0

SYNC/PWM

U/D

LX2

PIN

DESCRIPTION

1 inductor connection 1

2 DC/DC shut-down input

3 LDO2 shut-down input

4 up mode: DC/DC output;

down mode DC/DC input

5 current limiting resistor

connection

6 LDO1 output

7 LDO1 feedback input

8 internal supply ground

9 LDO2 feedback input

10 LDO2 output

11 LDO2 input

12 low battery detector input 2

13 low battery detector input 1

14 low battery detector output

15 reference voltage

16 DC/DC feedback input

17 DC/DC converter ground

18 synchronization clock input or

PWM-only selection input

19 conversion mode selection input

20 inductor connection 2

handbook, halfpage

LX1 1

20 LX2

SHDWN0 2

19 U/D

SHDWN2 3

18 SYNC/PWM

UPOUT/DNIN 4

17 GND0

ILIM 5

16 FB0

TEA1202TS

OUT1 6

15 Vref

FB1 7

14 LBO

GND 8

13 LBI1

FB2 9

12 LBI2

OUT2 10

11 IN2

MGU060

Fig.2 Pin configuration.

FUNCTIONAL DESCRIPTION

Control mechanism

The TEA1202TS DC/DC converter is able to operate in

PFM (discontinuous conduction) or PWM (continuous

conduction) operating mode. All switching actions are

completely determined by a digital control circuit which

uses the output voltage level as its control input. This novel

digital approach enables the use of a new pulse width and

frequency modulation scheme, which ensures optimum

power efficiency over the complete range of operation of

the converter.

When high output power is requested, the device will

operate in PWM (continuous conduction) operating mode.

This results in minimum AC currents in the circuit

components and hence optimum efficiency, minimum

costs and low EMC. In this operating mode, the output

voltage is allowed to vary between two predefined voltage

levels. As long as the output voltage stays within this

so-called window, switching continues in a fixed pattern.

When the output voltage reaches one of the window

borders, the digital controller immediately reacts by

adjusting the pulse width and inserting a current step in

such a way that the output voltage stays within the window

with higher or lower current capability. This approach

enables very fast reaction to load variations. Figure 3

shows the response of the converter to a sudden load

increase. The upper trace shows the output voltage.

The ripple on top of the DC level is a result of the current

in the output capacitor, which changes in sign twice per

cycle, times the internal Equivalent Series Resistance

(ESR) of the capacitor. After each ramp-down of the

inductor current, i.e. when the ESR effect increases the

output voltage, the converter determines what to do in the

next cycle. As soon as more load current is taken from the

output the output voltage starts to decay.

2000 Jun 08

5

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