TDA8939TH Datasheet, PDF (6/21 Pages) NXP Semiconductors – Zero dead time Class-D 7.5 A power comparator

Philips Semiconductors
TDA8939
Zero dead time Class-D 7.5 A power comparator
The block diagram of diagnostic output including OTP, OCP and OVP is illustrated in
Figure 3. The diagnostic output (pin 7) is an open-drain output; a pull-up resistor
connected to +V_pull-up has to be applied externally.
OTP
OCP
OVP
+V_int
R1
R2
TDA8939
disable power stage
S
C1
LATCH
R
Q
+V_pull-up
open-drain
Rpu
DIAGN
enable
001aaa623
CGND
Fig 3. OCP, OTP and OVP protection: S/R latch.
8.3 Interfacing between controller and the TDA8939
For interfacing with a digital PWM controller IC or microcontroller in the final system
application the following inputs and outputs are available see Table 4 and 5.
8.3.1 Inputs
Table 4: Inputs
Pin name
Pin number
IN1P and
IN1N
4 and 2
IN2P and
IN2N
9 and 11
POWERUP 5
ENABLE
6
Description
full differential input for output channel 1; referenced with respect
to each other; common mode referenced to V_SSD
full differential input for output channel 2; referenced with respect
to each other; common mode referenced to V_SSD
standby switch; reference to CGND; at a LOW level the device is
in standby mode and consumes a very low standby current. At
HIGH level the device is DC-biased (switch-on of internal
reference voltages and currents). The device can only be
switched to full operating mode by the enable input, if the
power-up input is at HIGH level.
mode switch; reference to CGND; at a LOW level the power
D-MOS switches are open and the PWM output is floating; all
internal logic circuits are in reset condition. At a HIGH level the
power comparator is fully operational if the power-up input is also
at a HIGH level. In this condition the power comparator outputs
are controlled by the input pins (IN1P, IN1N, IN2P and IN2N); see
also Figure 6. The enable input signal is also used to reset the
protection latch.
9397 750 13023
Objective data sheet
Rev. 01 — 22 April 2004
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
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