tea1553t NXP Semiconductors, tea1553t Datasheet - Page 8

• Manufacturer Part Number: tea1553t
• Description: Tea1553t Greenchip Ii Smps Control Ic
• Manufacturer: NXP Semiconductors

NXP Semiconductors
TEA1553T_1
Product data sheet
7.5 VCO adjust
The VCOADJ pin can be used to set the VCO operation point. As soon as the peak
voltage on the sense resistor is controlled below half the voltage on the VCOADJ pin
(VCO
somewhat higher due to switch-off delay, see
about 50 mV lower (VCO
A current of typically 10 A flows out of the VCOADJ pin, enabling the VCO operation
point to be set with a single resistor. When a more low-ohmic connection is desired (e.g.
due to noise), a voltage divider can be made from the VCC5V pin (see
Fig 7. Implementation of STDBY and cycle skipping functionality
1
level), frequency reduction will start. (The actual peak voltage on R
VCOADJ
VCC5V
CTRL
1.5 V
V CTRL
5 V
Rev. 01 — 3 July 2007
2
level), when the minimum frequency is reached.
Vx
CURRENT COMPARATOR
2
V
I
Figure
OSCILLATOR
8.) The frequency reduction will stop
DRIVER
GreenChip II SMPS control IC
DRIVER
ISENSE
TEA1553T
© NXP B.V. 2007. All rights reserved.
Figure
sense
014aaa006
7).
will be
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