LAVA Computer MFG STS Product Family User Manual – A01
2 Vulcan St. Toronto, ON Tel: +1 416 674-5942 www.lavalink.com
18 of 20
Canada, M9W 1L2 Fax: +1 416 674-8262 Toll Free (US & Canada): 800 241-5282
With the TYPE jumper
installed
, the MODE pins are set to level sensitive operation. Not shorting the
MODE pins places the module in SimulCharge Mode. Shorting the MODE pins places the module in
Charge-Only Mode.
The TYPE jumper is
only
sampled on power up. The TYPE jumper would normally be left shorted or
opened to configure the behavior of the MODE pins for a given application.
Use of the on-board SimulCharge and Charge-Only indictor LEDs are application specific. The default
jumpers shown in the diagram enable the on-board LEDs. To disable use on the on-board LEDs, remove
the related jumper. An external LED can be driven from these connector blocks. The center pin on the
jumper block is positive. The “right” pin as viewed on the diagram is the negative pin. A 680 ohm current
limit resistor is always present. When using an external LED, the internal LED is not to be used; hence the
left 2 pins remain open.
External LED +
External LED -
Option 1: Internal LED
Option 2: External LED
On power up the Charge-Only LED is pulsed rapidly for 2 seconds. After the initial 2 seconds, power to the
tablet is applied and the active mode (SimulCharge or Charge-Only) is set.
The Optional Power Connector is a DC Barrel Power Jack with a 2-millimeter center positive pin. This
connector is an OEM option, and therefore is not populated on the standard model. This jack in used in lieu
of the Micro USB-B receptacle for 5V power input. The jack is rated for up to 3.5 amperes. The jack is to
be connected to a regulated 5 volt DC power source.
Due to power loss across the connecting cables, the designer must ensure that the voltage at no point in the
system is too low. Power loss is an issue that applies to all USB cables in the system.
Using the Optional Power Connector allows for heaver gauge wires to the used, than are possible with a
Micro USB-B connector. The heavier gauge wires have lower power loss, and therefore permit the power
supply to be located farther from the module.
The power supply used to run the system is responsible for handling over current conditions.
The Optional Power Connector has no protection against over voltage or reversed power connections.
Application of the wrong voltage can result in immediate damage to the module, and possibly other
components in the system.
