E981.18A39FB ELMOS Semiconductor, E981.18A39FB Datasheet - Page 26

• Manufacturer Part Number: E981.18A39FB
• Description: Motor / Motion / Ignition Controllers & Drivers 8ch squib driver
• Manufacturer: ELMOS Semiconductor
• Type: Airbag Squib Driverr

Specifications of E981.18A39FB

• Rohs: yes
• Product: Electromechanical Drivers
• Operating Supply Voltage: 5 V
• Supply Current: 4.3 mA
• Operating Temperature: - 40 C to + 95 C
• Mounting Style: SMD/SMT
• Package / Case: QFN-44
• Number Of Outputs: 8
• Power Dissipation: 3.2 W

8-Channel Airbag Squib Driver
PRELIMINARY INFORMATION - AUG 01, 2011
The HSD control loop consists of:
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•
•
•
•
•
TxU Short circuit detection:
The short circuit comparator is enabled when the HSD is active.
In normal mode, as the LSD is activated prior the HSD, the SC comparator is enabled after a delay
T
comparator threshold. Then, if during deployment, a SC condition is detected, the SC_TxU flag is set in
the MISO register (but the HSD is not deactivated).
In Test Mode, in order to reduced as much as possible the energy provided to the squib in case in
intermittent SC to GND, the SC comparator is activated without any delay (T
a SC condition is detected, the SC_TxU flag is set in the MISO register and the HSD is deactivated.
The timing diagram is shown in Fig. 12
All 8 SC
The parameter T
Firing Time Limiter (FTL):
The Firing Time Limiter (FTL) is realized as a backward counter. The start value is given by the
according current mode (LCM/HCM), configurable by SPI. The Counter is active during Deployment
mode and Test-Up Mode. During TEST-Up Mode, the counter value is coupled to the selected current
modes (SPI CMD's 0x76 or 0x7C), too. The principle of the state transitions of the counter is sketched
in Fig. 13.
This document contains information on a pre-production product. ELMOS Semiconductor AG reserves the right to change specifications and information herein without notice.
ELMOS Semiconductor AG
SC_DEL_NM
LSD ON
HSD ON
V(TxU)
SC_TxU_ref
I(TxU)
reduced
SC_comp_out
SC_EN_out
SC_TxU
external ARM signal.
UNLOCK Latch set by SPI CMD (Reset conditions are given in chapter 5.14).
TEST_UP Latch set by SPI CMD (Reset conditions are given in chapter 5.14);
TEST_UP allows the activation of HSD in Test Mode (current limit reduced) independently of ARM
and CODELOCK signals.
TxU
SC
pins.
FTL_TxU signal coming from the Firing Time Limiter, one for each driver.
TxU
ON
TxU
signal coming from the driver output stage, which detects a short circuit to GND at the TxU
, in order to let the HSD conducting a minimum current to allow the TxU pin exceeding the SC
Latch set by SPI CMD; one for each driver (Reset conditions are given in chapter 5.14).
signals are summarized in one MISO status Bit. (see chapter 5.4.5).
SC_EN_NM
Fig. 12 Timing diagram SC detection for deployment mode
is given in 5.11.2.
T
SC_DEL_NM
Page 26 of 63
Data Sheet
Faultback mode: Ilim
SC_DEL_TM
QM-No.: 25DS0072E.00
= 0µs). As soon as
E981.18