TDA8939TH Datasheet, PDF (7/21 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
8.3.2 Outputs
Table 5: Outputs
Pin name
Pin number
DIAGN
7
Description
Digital open-drain output; referenced to CGND; output indicates
the following fault conditions: OTP, OCP, OVP and UVP. In the
event of a fault condition the output is pulled to the CGND voltage
(active LOW). If the diagnostic output functionality is used in the
application, an external pull-up resistor is required.
8.3.3 Reference voltages
Table 6: Reference voltages
Pin name
Pin number
CGND
8
V_SSD
24
Description
common ground; reference ground for diagnostic
output, enable input and power-up input
negative digital supply; reference ground digital circuits.
The V_SSD pin should be connected to V_SS voltage in the
application. Internally the V_SSD pin is connected to the
V_SSAx and V_SSPx (e.g. V_SSA1 and V_SSP1) via an ESD
protection diode.
8.4 Start-up timing
Power comparator mode selection:
• Standby mode: when pin POWERUP is LOW, the power comparator is in standby
mode, independent of the signal on the enable input
• Reset mode: when pin POWERUP is HIGH, the status of the power comparator is
controlled by pin ENABLE; if pin ENABLE is LOW, the status of the power stage is
reset and the outputs are floating
• Operating mode: when pin ENABLE is HIGH, the power stage is in operating mode.
To ensure correct start-up of the power stage, the enable input should never be HIGH
when the power-up input is LOW. Before switching to operating mode, the amplifier should
first be switched to reset mode.
Remark: It is possible to directly connect the power-up input to the positive supply line
(e.g. V_DDA1). As soon as the supply voltage is applied the device will be DC-biased (reset
mode).
Table 7: Mode selection
Pin
POWERUP
LOW
HIGH
HIGH
ENABLE
X
LOW
HIGH
Mode
standby
reset
operating
9397 750 13023
Objective data sheet
Rev. 01 — 22 April 2004
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
7 of 21