 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
L9945 Datasheet(PDF) 26 Page - STMicroelectronics |
|
|
|||||||||||||||||||||||||||||
L9945 Datasheet(HTML) 26 Page - STMicroelectronics |
|
|
26 / 151 page  In case GCC_config_xx is programmed "0b00", an external resistor RG is required for protecting the transistor gate against excessive current: the resistor must be mounted in series on the IPU / IPD path, as shown in Figure 12. However, to prevent charge pump stress, L9945 internally limits the maximum charge/discharge current to ICh0Gx/IDCh0Gx (refer to Table 15). External measures have to be taken to keep the external MOS reliably OFF in case of output three-state. For external NMOS a gate pull down resistor RPD is needed and for external PMOS a gate pull up resistor RPU is necessary (refer to Figure 12). In order to improve EMI behavior, an external Miller capacitor CM can be mounted between transistor gate and drain. Value of this capacitor depends on: • The switching frequency required by the application; • The programmed charge/discharge current. The AN "How To Improve EMI Behavior In Switching Applications" provides a guideline for CM selection. It also helps choosing the right value for IPU/IPD in order to reduce EMI. 5.4.5 Internal and external clamping The device guarantees a maximum gate to source voltage of 20 V by means of an internal clamping circuitry which limits the overdrive. However, such a clamp is not intended as a protection against external spikes or failures (STB/STG). Figure 13. Clamping for HS configuration GADG2702171244PS GNSPxx To load VPS CM IPU IPD VGBHI Internal clamping Control signal Control signal D Ratings: NMOS ==> VGS = 20 V , PMOS ==> VSG = 20 V evice side Board side HS NFET VPS GNSPxx SNGPxx DRNxx External clamping CM IPU IPD Internal clamping To load Control signal Control signal Device side Board side HS PFET SNGPxx DRNxx External clamping RPU RG RG Figure 13 shows the recommended clamping for the external FETs used in HS configuration. The internal clamping is meant to protect against overdrive but is not intended to be a recirculation path for the current. An external freewheeling diode is needed for inductive switching loads. L9945 Output pre-drivers DS12275 - Rev 8 page 26/151 |
|
Link URL |
| Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link to Datasheet | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
| Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
|
Family Site : ic2ic.com |
icmetro.com |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
