L6598D013TR ,HIGH VOLTAGE RESONANT CONTROLLERL6598HIGH VOLTAGE RESONANT CONTROLLERFigure 1. Packages1
L6599A ,IMPROVED HIGH-VOLTAGE RESONANT CONTROLLERAbsolute maximum ratings . . . . . 84.2 Thermal data . . . . . . . 85
L6599AD ,IMPROVED HIGH-VOLTAGE RESONANT CONTROLLERElectrical characteristics . . . . . 96 Typical electrical performance 127 Application inf ..
L6599ADTR ,IMPROVED HIGH-VOLTAGE RESONANT CONTROLLERL6599AImproved high-voltage resonant controllerDatasheet − production data
L6599ATD ,IMPROVED HIGH-VOLTAGE RESONANT CONTROLLERElectrical characteristics . . . . . 96 Application information . . . . . 126.1 Oscillato ..
L6599ATDTR ,IMPROVED HIGH-VOLTAGE RESONANT CONTROLLERFeaturesTable 1. Device summary 50% duty cycle, variable frequency control of Order code Package P ..
LC4032V-75TN44I , 3.3V/2.5V/1.8V In-System Programmable SuperFAST High Density PLDs
LC4032ZC-75M56C , 3.3V/2.5V/1.8V In-System Programmable SuperFAST High density PDLs
LC4032ZE-5TN48I , 1.8V In-System Programmable Ultra Low Power PLDs
LC4064B-25T48C , 3.3V/2.5V/1.8V In-System Programmable SuperFAST High Density PLDs
LC4064B-75TN48C , 3.3V/2.5V/1.8V In-System Programmable SuperFAST High Density PLDs
LC4064V-10T100I , 3.3V/2.5V/1.8V In-System Programmable SuperFAST High Density PLDs
L6598D013TR
HIGH VOLTAGE RESONANT CONTROLLER
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L6598June 2004
FEATURES HIGH VOLTAGE RAIL UP TO 600V dV/dt IMMUNITY ±50V/ns IN FULL
TEMPERATURE RANGE DRIVER CURRENT CAPABILITY:
250mA SOURCE
450mA SINK SWITCHING TIMES 80/40ns RISE/FALL WITH
1nF LOAD CMOS SHUT DOWN INPUT UNDER VOLTAGE LOCK OUT SOFT START FREQUENCY SHIFTING
TIMING SENSE OP AMP FOR CLOSED LOOP
CONTROL OR PROTECTION FEATURES HIGH ACCURACY CURRENT CONTROLLED
OSCILLATOR INTEGRATED BOOTSTRAP DIODE CLAMPING ON Vs SO16, DIP16 PACKAGES
DESCRIPTIONThe device is manufactured with the BCD OFF LINE
technology, able to ensure voltage ratings up to
600V, making it perfectly suited for AC/DC Adapters
and wherever a Resonant Topology can be benefi-
cial. The device is intended to drive two Power MOS,
in the classical Half Bridge Topology. A dedicated
Timing Section allows the designer to set Soft Start
Time, Soft Start and Minimum Frequency. An Error
Amplifier, together with the two Enable inputs, are
made available. In addition, the integrated Bootstrap
Diode and the Zener Clamping on low voltage sup-
ply, reduces to a minimum the external parts needed
in the applications.
HIGH VOLTAGE RESONANT CONTROLLER
Figure 2. Block Diagram
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Figure 3. Pin Connection
Table 2. Thermal Data
Table 3. Pin Function
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Table 4. Absolute Maximum Ratings(*) The device is provided of an internal Clamping Zener between GND and the Vs pin, It must not be supplied by a low impedance voltage
source.
Note : ESD immunity for pins 14, 15 and 16 is guaranteed up to 900 (Human Body Model).
Table 5. Recommended Operating Conditions(*) If the condition Vboot - Vout < 18 is guaranteed, Vout can range from -3 to 580V.
L6598
Table 6. Electrical Characteristcs (VS = 12V; VBOOT - VOUT = 12V; Tamb = 25°C)
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L6598(*) Guaranted by design
Figure 5. EN1 Timing Diagrams
Table 6. Electrical Characteristcs (continued)(VS = 12V; VBOOT - VOUT = 12V; Tamb = 25°C)
L6598
Figure 6. Oscillator/Output Timing Diagram BLOCK’S DIAGRAM DESCRIPTION
3.1 High/Low Side driving sectionAn High and Low Side driving Section provide the proper driving to the external Power MOS or IGBT. An high
sink/source driving current (450/250 mA typ) ensure fast switching times also when size4 Power MOS are used.
The internal logic ensures a minimum dead time to avoid cross-conduction of the power devices.
3.2 Timing and Oscillator SectionThe device is provided of a soft start function. It consists in a period of time, TSS, in which the switching frequen-
cy shifts from fstart to fmin. This feature is explained in the following description (ref. fig.7 and fig.8).
Figure 7. Soft Start and frequency shifting block
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L6598During the soft start time the current ISS charges the capacitor CSS, generating a voltage ramp which is delivered
to a transconductance amplifier, as shown in fig. 7. Thus this voltage signal is converted in a growing current
which is subtracted to Ifstart. Therefore the current which drives the oscillator to set the frequency during the soft
start is equal to:
[1]
where [2]
At the start-up (t=0) the oscillator frequency is set by:
[3]
At the end of soft start (t = TSS) the second term of eq.1 decreases to zero and the switching frequency is set
only by Imin (i.e. Rfmin):
[4]
Since the second term of eq.1 is equal to zero, we have:
[5]
Note that there is not a fixed threshold of the voltage across CSS in which the soft start finishes (i.e. the end of
the frequency shifting), and TSS depends on CSS, Ifstart, gm, and ISS (eq. 5). Making TSS independent of Ifstart,
the ISS current has been designed to be a fraction of Ifstart, so:
[6]
In this way the soft start time depends only on the capacitor CSS. The typical value of the kSS constant (Soft
Start Timing Constant) is 0.15 s/µF.
The current Iosc is fed to the oscillator as shown in fig. 7. It is twice mirrored (x4 and x8) generating the triangular
wave on the oscillator capacitor Cf. Referring to the internal structure of the oscillator (fig.7), a good relationship
to compute an approximate value of the oscillator frequency in normal operation is:
[7]
The degree of approximation depends on the frequency value, but it remains very good in the range from 30kHz
to 100kHz (figg.9-13) osc I fmin I fstart gmV Csst()– ()+ I fmin I fstartmIssss------------t– +== fmin REF fmin
--------------I fsart, V REF fstart
----------------V REF, 2V== = osc0() I fmin I fstart+ V REF 1 fmin------------ 1 fstart--------------+ == oscTss() I fmin REF fmin------------== fstartmIssss------------TSS– 0TSS→ CssI fstartmIss----------------------==SS fstart-------------- TSS→ CssI fstartmI fstartK-------------------------- TSS→ CssmK----------- TSS kSSCSS–→== = min 1.41 fminCf-------------------=
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Figure 8. Oscillator Block
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Figure 9. Typ. fmin vs. Rfmin @ Cf = 470pF
Figure 10. Typ. (fstart-fmin) vs. Rfstar @
Cf = 470pF
Figure 11. Typ. (fstart-fmin) vs. Rfstar @
Cf = 470pF
Figure 12. Typ. (fstart-fmin) vs. Rfstar @
Cf = 470pF
Figure 13. fmin @ different Rf vs Cf
